Term
|
Definition
| A two-wire STP implementation of Gigabit Ethernet. |
|
|
Term
|
Definition
| A two-wire fiber implementation of Gigabit Ethernet using long-wave laser. |
|
|
Term
|
Definition
| A two-wire fiber implementation of Gigabit Ethernet using short-wave laser signals. |
|
|
Term
|
Definition
| A four-wire UTP implementation of Gigabit Ethernet. |
|
|
Term
|
Definition
| A two-wire fiber implementation of Fast Ethernet. |
|
|
Term
|
Definition
| A four-wire UTP implementation of Fast Ethernet. |
|
|
Term
|
Definition
| A two-wire UTP implementation of Fast Ethernet. |
|
|
Term
|
Definition
| The thin coaxial cable implementation of Standard Ethernet. |
|
|
Term
|
Definition
| The thick coaxial cable implementation of Standard Ethernet. |
|
|
Term
|
Definition
| The extended implementation of Ten-Gigabit Ethernet. |
|
|
Term
|
Definition
| The fiber implementation of Standard Ethernet. |
|
|
Term
|
Definition
| A fiber implementation of Ten-Gigabit Ethernet using long-wave laser. |
|
|
Term
|
Definition
| A fiber implementation of Ten-Gigabit Ethernet using short-wave laser. |
|
|
Term
|
Definition
| The twisted-pair implementation of Standard Ethernet. |
|
|
Term
|
Definition
| A CSMA persistence strategy in which a station sends a frame immediately if the line is idle. |
|
|
Term
|
Definition
| A line encoding technique in which each pulse represents 2 bits. |
|
|
Term
|
Definition
| A block coding technique in which 4 bits are encoded into a 5-bit code. |
|
|
Term
| 4-dimensional, 5-level pulse amplitude modulation (4D-PAM5) |
|
Definition
| An encoding scheme used by 1000Base-T. |
|
|
Term
|
Definition
| A modem technology using two different data rates: one for uploading and one for downloading from the Internet. |
|
|
Term
|
Definition
| A telephone service free to the caller. |
|
|
Term
|
Definition
| A block coding technique in which 8 bits are encoded into a 10-bit code. |
|
|
Term
|
Definition
| A block coding technique in which 8 bits are encoded into a 6-bit code. |
|
|
Term
|
Definition
| A telephone service paid by the caller. |
|
|
Term
| Abstract Syntax Notation 1 (ASN.1) |
|
Definition
| A standard for representing simple and structured data. |
|
|
Term
|
Definition
| The determination of link control through a data link protocol. |
|
|
Term
|
Definition
| A central base station in a BSS. |
|
|
Term
|
Definition
| In Frame Relay, the data rate that can never be exceeded. |
|
|
Term
|
Definition
| A response sent by the receiver to indicate the successful receipt and acceptance of data. |
|
|
Term
|
Definition
| In the client-server model, the closing of a communication by the client. |
|
|
Term
|
Definition
| In the World Wide Web, a document executed at the local site using Java. |
|
|
Term
|
Definition
| In the client-server model, the opening of a communication by the client. |
|
|
Term
| adaptive delta modulation |
|
Definition
| A delta modulation technique in which the value of delta changes according to the amplitude of the analog signal. |
|
|
Term
|
Definition
| A SONET device that multiplexes signals from different sources or demultiplexes a signal to multiple destinations. |
|
|
Term
|
Definition
| With slow start, a congestion avoidance strategy in which the window size is increased by just one segment instead of exponentially. |
|
|
Term
|
Definition
| A mechanism in which the blocks of addresses for several organizations are aggregated into one larger block. |
|
|
Term
| Address Resolution Protocol (ARP) |
|
Definition
| In TCP/IP, a protocol for obtaining the physical address of a node when the Internet address is known. |
|
|
Term
|
Definition
| The total number of addresses used by a protocol. |
|
|
Term
| address-mask request and reply ICMP |
|
Definition
| Messages that find the network mask. |
|
|
Term
|
Definition
| A splitterless ADSL. This technology allows an ASDL Lite modem to be plugged directly into a telephone jack and connected to the computer. The splitting is done at the telephone company. |
|
|
Term
| Advanced Encryption Standard (AES) |
|
Definition
| A secret-key cryptosystem adapted by NIST to replace DES. |
|
|
Term
| Advanced Mobile Phone System (AMPS) |
|
Definition
| A North American analog cellular phone system using FDMA. |
|
|
Term
| Advanced Research Projects Agency (ARPA) |
|
Definition
| The government agency that funded ARPANET. |
|
|
Term
| Advanced Research Projects Agency Network (ARPANET) |
|
Definition
| The packet-switching network that was funded by ARPA. |
|
|
Term
|
Definition
| The original random multiple access method in which a station can send a frame any time it has one to send. |
|
|
Term
| alternate mark inversion (AMI) |
|
Definition
| A digital-to-digital bipolar encoding method in which the amplitude representing 1 alternates between positive and negative voltages. |
|
|
Term
| American National Standards Institute (ANSI) |
|
Definition
| A national standards organization that defines standards in the United States. |
|
|
Term
| American Standard Code for Information Interchange (ASCII) |
|
Definition
| A character code developed by ANSI and used extensively for data communication. |
|
|
Term
|
Definition
| The strength of a signal, usually measured in volts, amperes, or watts. |
|
|
Term
| amplitude modulation (AM) |
|
Definition
| An analog-to-analog conversion method in which the carrier signal's amplitude varies with the amplitude of the modulating signal. |
|
|
Term
| amplitude shift keying (ASK) |
|
Definition
| A modulation method in which the amplitude of the carrier signal is varied to represent binary 0 or 1. |
|
|
Term
|
Definition
| A continuously varying entity. |
|
|
Term
|
Definition
| Data that are continuous and smooth and not limited to a specific number of values. |
|
|
Term
|
Definition
| A telephone company system in which multiplexed signals are combined into successively larger groups for more efficient transmission. |
|
|
Term
|
Definition
| A service featuring a dedicated line between two users. |
|
|
Term
|
Definition
| A continuous waveform that changes smoothly over time. |
|
|
Term
|
Definition
| A temporary analog connection between two users. |
|
|
Term
| analog-to-analog modulation |
|
Definition
| The representation of analog information by an analog signal. |
|
|
Term
| analog-to-digital conversion |
|
Definition
| The representation of analog information by a digital signal. |
|
|
Term
|
Definition
| In optics, the angle formed by a light ray approaching the interface between two media and the line perpendicular to the interface. |
|
|
Term
|
Definition
| A protocol in which a remote user can access another machine without an account or password. |
|
|
Term
|
Definition
| An address that defines a group of computers with addresses that have the same beginning. |
|
|
Term
|
Definition
| A signal that does not exhibit a pattern or repeating cycle. |
|
|
Term
|
Definition
| A computer program for creating an active Web document. It is usually written in Java. |
|
|
Term
| application adaptation layer (AAL) |
|
Definition
| A layer in ATM protocol that breaks user data into 48-byte payloads. |
|
|
Term
|
Definition
| The fifth layer in the Internet model; provides access to network resources. |
|
|
Term
| application programming interface (API) |
|
Definition
| A set of declarations, definitions, and procedures followed by programmers to write client-server programs. |
|
|
Term
|
Definition
| A collection of networks, hosts, and routers all contained within an autonomous system. |
|
|
Term
|
Definition
| A router inside an area that summarizes the information about the area and sends it to other areas. |
|
|
Term
|
Definition
| A 32-bit field that defines the area within which the routing takes place. |
|
|
Term
|
Definition
|
|
Term
| asymmetric digital subscriber line (ADSL) |
|
Definition
| A communication technology in which the downstream data rate is higher than the upstream rate. |
|
|
Term
| asynchronous balanced mode (ABM) |
|
Definition
| In HDLC, a communication mode in which all stations are equal. |
|
|
Term
| asynchronous connectionless link (ACL) |
|
Definition
| A link between a Bluetooth master and slave in which a corrupted payload is retransmitted. |
|
|
Term
| Asynchronous Transfer Mode (ATM) |
|
Definition
| A wide area protocol featuring high data rates and equal-sized packets (cells); ATM is suitable for transferring text, audio, and video data. |
|
|
Term
| asynchronous transmission |
|
Definition
| Transfer of data with start and stop bit(s) and a variable time interval between data units. |
|
|
Term
|
Definition
| A LAN using ATM technology. |
|
|
Term
|
Definition
| A layer in ATM that provides routing, traffic management, switching, and multiplexing services. |
|
|
Term
|
Definition
| An ATM device providing both switching and multiplexing functions. |
|
|
Term
| attachment unit interface (AUI) |
|
Definition
| A 10Base5 cable that performs the physical interface functions between the station and the transceiver. |
|
|
Term
|
Definition
| The loss of a signal's energy due to the resistance of the medium. |
|
|
Term
|
Definition
| Recording or transmitting of sound or music. |
|
|
Term
|
Definition
| In PPP, an optional state that verifies the identity of the receiver. |
|
|
Term
|
Definition
| Verification of the sender of a message. |
|
|
Term
| Authentication Header (AH) Protocol |
|
Definition
| A protocol defined by IPSec at the network layer that provides integrity to a message through the creation of a digital signature by a hashing function. |
|
|
Term
| authentication server (AS) |
|
Definition
| The KDC in the Kerberos protocol. |
|
|
Term
| automatic repeat request (ARQ) |
|
Definition
| An error-control method in which correction is made by retransmission of data. |
|
|
Term
|
Definition
| Tunneling in which the receiving host has an IPv6 compatible address; no reconfiguration is necessary. |
|
|
Term
|
Definition
| A Fast Ethernet feature that allows two devices to negotiate the mode or data rate. |
|
|
Term
|
Definition
| A group of networks and routers under the authority of a single administration. |
|
|
Term
| autonomous system boundary router |
|
Definition
| Routers responsible for dissipating information about other autonomous systems into the current system. |
|
|
Term
|
Definition
| The minimum data rate in ATM at which cells can be delivered. |
|
|
Term
|
Definition
| In multiple access, waiting before re-sending after a collision. |
|
|
Term
|
Definition
| A network that connects smaller networks in an organization. |
|
|
Term
|
Definition
| A router inside the backbone. |
|
|
Term
| backward explicit congestion notification (BECN) |
|
Definition
| A bit in the Frame Relay packet that notifies the sender of congestion. |
|
|
Term
|
Definition
| A channel that can pass a range of frequencies. |
|
|
Term
|
Definition
| The difference between the highest and the lowest frequencies of a composite signal. It also measures the information-carrying capacity of a line or a network. |
|
|
Term
|
Definition
| A digital service that allows subscribers higher speeds through the use of multiple lines. |
|
|
Term
|
Definition
| A measure of the number of bits that can be sent while waiting for news from the receiver. |
|
|
Term
|
Definition
| A multistage switch with microswitches at each stage that route the packets based on the output port represented as a binary string. |
|
|
Term
|
Definition
| A sequence of 11 bits used for spreading. |
|
|
Term
|
Definition
| In IPv6, the main header of the datagram. |
|
|
Term
|
Definition
| Transmission of digital or analog signal without modulation using a low-pass channel. |
|
|
Term
|
Definition
| In decoding a digital signal, the receiver calculates a running average of the received signal power. This average is called the baseline. A long string of 0s and 1s can cause a drift in the baseline (baseline wandering) and make it difficult for the receiver to decode correctly. |
|
|
Term
| Basic Encoding Rule (BER) |
|
Definition
| A standard that encodes data to be transferred through a network. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| The building block of a wireless LAN as defined by the IEEE 802.11 standard. |
|
|
Term
|
Definition
| The number of signal elements transmitted per second. A signal element consists of one or more bits. |
|
|
Term
| Bayone-Neill-Concelman (BNC) connector |
|
Definition
| A common coacxial cable connector. |
|
|
Term
|
Definition
| The unreliable transmission mechanism by IP that does not guarantee message delivery. |
|
|
Term
| bidirectional authentication |
|
Definition
| An authentication method involving a challenge and a response from sender to receiver and vice versa. |
|
|
Term
| bidirectional frame (B-frame) |
|
Definition
| An MPEG frame that is related to the preceding and following I-frame or P-frame. |
|
|
Term
| binary exponential backup |
|
Definition
| In contention access methods, a retransmission delay strategy used by a system to delay access. |
|
|
Term
|
Definition
| Representation of IP addresses in binary. |
|
|
Term
|
Definition
| A type of polar encoding where the signal changes at the middle of the bit interval. Manchester and differential Manchester are examples of biphase encoding. |
|
|
Term
|
Definition
| A digital-to-digital encoding method in which 0 amplitude represents binary 0 and positive and negative amplitudes represent alternate 1s. |
|
|
Term
| bipolar n-zero substitution (BnZS) |
|
Definition
| An encoding method to provide synchronization for long strings of 0s. |
|
|
Term
| bipolar with 8-zero substitution (B8ZS) |
|
Definition
| A scrambling technique in which a stream of 8 zeros are replaced by a predefined pattern to improve bit synchronization. |
|
|
Term
|
Definition
| binary digit; the smallest unit of data(0 or 1) |
|
|
Term
|
Definition
| The time required to send one bit. |
|
|
Term
|
Definition
| In TDM, the addition of extra bits to a device's source stream to force speed relationships. |
|
|
Term
|
Definition
| The number of bits transmitted per second. |
|
|
Term
|
Definition
| In a bit-oriented protocol, the process of adding an extra bit in the data section of a frame to prevent a sequence of bits from looking like a flag. |
|
|
Term
|
Definition
| A protocol in which the data frame is interpreted as a sequence of bits. |
|
|
Term
|
Definition
| A measurement of data speed; bits transmitted per second. |
|
|
Term
|
Definition
| An encryption/decryption algorithm that has a block of bits as its basic unit. |
|
|
Term
|
Definition
| An error detection/correction code in which data are divided into units called datawords. Redundant bits are added to each dataword to create a codeword. |
|
|
Term
|
Definition
| A coding method to ensure synchronization and detection of errors. |
|
|
Term
|
Definition
| An event that occurs when a switching network is working at its full capacity and cannot accept more input. |
|
|
Term
|
Definition
| A port on a bridge that does not forward a frame. |
|
|
Term
|
Definition
| A wireless LAN technology designed to connect devices of different functions such as telephones and notebooks in a small area such as a room. |
|
|
Term
|
Definition
| A common coaxial cable connector. |
|
|
Term
| Bootstrap Protocol (BOOTP) |
|
Definition
| The protocol that provides configuration information from a table (file). |
|
|
Term
| Border Gateway Protocol (BGP) |
|
Definition
| An interautonomous system routing protocol based on path vector routing. |
|
|
Term
|
Definition
| A network device operating at the first two layers of the Internet model with filtering and forwarding capabilities. |
|
|
Term
|
Definition
| Transmission of signals using modulation of a higher frequency signal. The term implies a wide-bandwidth data combined from different sources. |
|
|
Term
|
Definition
| An address that allows transmission of a message to all nodes of a network. |
|
|
Term
| broadcast/unknown server (BUS) |
|
Definition
| A server connected to an ATM switch that can multicast and broadcast frames. |
|
|
Term
|
Definition
| Transmission of a message to all nodes in a network. |
|
|
Term
|
Definition
| An application program that displays a WWW document. A browser usually uses other Internet services to access the document. |
|
|
Term
|
Definition
| In a wireless LAN, a station that can move from one BSS to another but is confined inside one ESS. |
|
|
Term
|
Definition
| See man-in-the middle attack |
|
|
Term
|
Definition
| Error in a data unit in which two or more bits have been altered. |
|
|
Term
|
Definition
| Data with varying instantaneous transmission rates. |
|
|
Term
|
Definition
| A network topology in which all computers are attached to a shared medium. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| In a byte-oriented protocol, the process of adding an extra byte in the data section of a frame to prevent a byte from looking like a flag. |
|
|
Term
|
Definition
| A protocol in which the data section of the frame is interpreted as a sequence of bytes (characters). |
|
|
Term
|
Definition
| A technology in which the TV cable provides Internet access. |
|
|
Term
| cable modem transmission system (CMTS) |
|
Definition
| A device installed inside the distribution hub that receives data from the Internet and passes them to the combiner. |
|
|
Term
|
Definition
| A system using coaxial or fiber optic cable that brings multiple channels of video programs into homes. |
|
|
Term
|
Definition
| The storing of information in a small, fast memory. |
|
|
Term
|
Definition
| A shift cipher used by Julius Caesar with the key value of 3. |
|
|
Term
|
Definition
| A technique in Gigabit Ethernet that increases the minimum length of the frame to achieve a higher maximum cable length. |
|
|
Term
| carrier sense multiple access (CSMA) |
|
Definition
| A contention access method in which each station listens to the line before transmitting data. |
|
|
Term
| carrier sense multiple access with collision avoidance (CSMA/CA) |
|
Definition
| An access method in which collision is avoided. |
|
|
Term
| carrier sense multiple access with collision detection (CSMA/CD) |
|
Definition
| An access method in which stations transmit whenever the transmission medium is available and retransmit when collision occurs. |
|
|
Term
|
Definition
| A high frequency signal used for digital-to-analog or analog-to-analog modulation. One of the characteristics of the carrier signal (amplitude, frequency, or phase) is changed according to the modulating data. |
|
|
Term
|
Definition
| A small, fixed-size data unit; also, in cellular telephony, a geographical area served by a cell office. |
|
|
Term
|
Definition
| A network using the cell as its basic data unit. |
|
|
Term
|
Definition
| A wireless communication technique in which an area is divided into cells. A cell is served by a transmitter. |
|
|
Term
| Certification Authority (CA) |
|
Definition
| An agency such as a federal or state organization that binds a public key to an entity and issues a certificate. |
|
|
Term
| Challenge Handshake Authentication Protocol (CHAP) |
|
Definition
| In PPP, a three-way handshaking protocol used for authentication. |
|
|
Term
|
Definition
| A communications pathway. |
|
|
Term
|
Definition
| A multiple access method in which the available bandwidth of a link is shared in time. |
|
|
Term
| character-oriented protocol |
|
Definition
| See byte-oriented protocol |
|
|
Term
|
Definition
| A field used for error detection. It is formed by adding bit streams using one's complement arithmetic and then complementing the result. |
|
|
Term
|
Definition
| In CDMA, a number in a code that is assigned to a station. |
|
|
Term
|
Definition
| A packet sent by a router to the source to inform it of congestion. |
|
|
Term
|
Definition
| A unit of transmission in SCTP. |
|
|
Term
|
Definition
| An encryption/decryption algorithm. |
|
|
Term
| cipher block chaining (CBC) mode |
|
Definition
| A DES and triple DES operation mode in which the encryption (or decryption) of a block depends on all previous blocks. |
|
|
Term
| cipher feedback mode (CFM) |
|
Definition
| A DES and triple DES operation mode in which data is sent and received 1 bit at a time, with each bit independent of the previous bits. |
|
|
Term
|
Definition
| A DES and triple DES operation mode in which data is sent and received 1 byte at a time. |
|
|
Term
|
Definition
| AA list of possible ciphers. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A switching technology that establishes an electrical connection between stations using a dedicated path. |
|
|
Term
|
Definition
| Glass or plastic surrounding the core of an optical fiber; the optical density of the cladding must be less than that of the core. |
|
|
Term
|
Definition
| An IPv4 address with the first octet between 0 and 127. |
|
|
Term
|
Definition
| An IPv4 address with the first octet between 128 and 191. |
|
|
Term
|
Definition
| An IPv4 address with the first octet between 192 and 223. |
|
|
Term
|
Definition
| An IPv4 multicast address. |
|
|
Term
|
Definition
| An IPv4 address reserved for special purposes. |
|
|
Term
|
Definition
| An IPv4 addressing mechanism in which the IP address space is divided into 5 classes: A, B, C, D, and E. Each class occupies some part of the whole address space. |
|
|
Term
|
Definition
| An addressing mechanism in which the IP address space is not divided into classes. |
|
|
Term
| Classless InterDomain Routing (CIDR) |
|
Definition
| A technique to reduce the number of routing table entries when supernetting is used. |
|
|
Term
|
Definition
| A running application program on a local site that requests service from a running application program on a remote site. |
|
|
Term
|
Definition
| The model of interaction between two application programs in which a program at one end (client) requests a service from a program at the other end (server). |
|
|
Term
| closed-loop congestion control |
|
Definition
| A method to alleviate congestion after it happens. |
|
|
Term
|
Definition
| A transmission medium consisting of a conducting core, insulating material, and a second conducting sheath. |
|
|
Term
| code division multiple access (CDMA) |
|
Definition
| A multiple access method in which one channel carries all transmissions simultaneously. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A dynamic web technology that allows the fusion of data items coming from a conventional database. |
|
|
Term
|
Definition
| The event that occurs when two transmitters send at the same time on a channel designed for only one transmission at a time; data will be destroyed. |
|
|
Term
|
Definition
| The length of the medium subject to collision. |
|
|
Term
|
Definition
| The maximum number of bits in a specific time period that a Frame Relay network must transfer without discarding any frames. |
|
|
Term
| committed information rate (CIR) |
|
Definition
| The committed burst size divided by time. |
|
|
Term
|
Definition
| A transmission facility available to the public and subject to public utility regulation. |
|
|
Term
| Common Gateway Interface (CGI) |
|
Definition
| A standard for communication between HTTP servers and executable programs. CGI is used in creating dynamic documents. |
|
|
Term
| community antenna TV (CATV) |
|
Definition
| A cable network service that broadcasts video signals to locations with poor or no reception. |
|
|
Term
|
Definition
| An IPv6 address consisting of 96 bits of zero followed by 32 bits of IPv4. |
|
|
Term
| competitive local exchange carrier (CLEC) |
|
Definition
| A telephone company that cannot provide main telephone services; instead, other services such as mobile telephone service and toll calls inside a LATA are provided. |
|
|
Term
| complementary code keying (CCK) |
|
Definition
| An HR-DSSS encoding method that encodes four or eight bits into one symbol. |
|
|
Term
|
Definition
| A signal composed of more than one sine wave. |
|
|
Term
|
Definition
| A client running the same time as another client of the same process. |
|
|
Term
|
Definition
| A server that can process many requests at the same time and share its time between many requests. |
|
|
Term
|
Definition
| Excessive network or internetwork traffic causing a general degradation of service. |
|
|
Term
|
Definition
| In Frame Relay, a method using two bits that explicitly notify the source and destination of congestion. |
|
|
Term
|
Definition
| A method to manage network and internetwork traffic to improve throughput. |
|
|
Term
|
Definition
| A tool that connects computers or networks. |
|
|
Term
|
Definition
| The technique used by the transport layer to deliver segments. |
|
|
Term
|
Definition
| The preliminary setup necessary for a logical connection prior to actual data transfer. |
|
|
Term
|
Definition
| A message sent to end a connection. |
|
|
Term
| connectionless iterative server |
|
Definition
| A connectionless server that processes one request at a time. |
|
|
Term
|
Definition
| A service for data transfer without connection establishment or termination. |
|
|
Term
| connection-oriented concurrent server |
|
Definition
| A connection-oriented server that can serve many clients at the same time. |
|
|
Term
| connection-oriented service |
|
Definition
| A service for data transfer involving establishment and termination of a connection. |
|
|
Term
|
Definition
| The data rate of an ATM service class that is designed for customers requiring real-time audio or video services. |
|
|
Term
|
Definition
| A graphical representation of the phase and amplitude of different bit combinations in digital-to-analog modulation. |
|
|
Term
| Consultative Committee for International Telegraphy and Telephony (CCITT) |
|
Definition
| An international standards group now known as the ITU-T. |
|
|
Term
|
Definition
| An access method in which two or more devices try to transmit at the same time on the same channel. |
|
|
Term
|
Definition
| The FTP connection used for control information (commands and responses). |
|
|
Term
|
Definition
| A multiple access method in which the stations consult one another to determine who has the right to send. |
|
|
Term
| convergence sublayer (CS) |
|
Definition
| In ATM protocol, the upper AAL sublayer that adds a header or a trailer to the user data. |
|
|
Term
|
Definition
| A string of characters that holds some information about the client and must be returned to the server untouched. |
|
|
Term
|
Definition
| The glass or plastic center of an optical fiber. |
|
|
Term
|
Definition
| In multicasting, a group-shared protocol that uses a center router as the root of the tree. |
|
|
Term
|
Definition
| A subdomain in the Domain Name System that uses two characters as the last suffix. |
|
|
Term
|
Definition
| The process that validates the CRC remainder. |
|
|
Term
|
Definition
| The process that creates the CRC remainder. |
|
|
Term
|
Definition
| In refraction, the value of the angle of incidence that produces a 90-degree angle of refraction. |
|
|
Term
|
Definition
| A switch consisting of a lattice of horizontal and vertical paths. At the intersection of each horizontal and vertical path, there is a crosspoint that can connect the input to the output. |
|
|
Term
|
Definition
| The junction of an input and an output on a crossbar switch. |
|
|
Term
|
Definition
| The noise on a line caused by signals traveling along another line. |
|
|
Term
|
Definition
| The science and art of transforming messages to make them secure and immune to attacks. |
|
|
Term
|
Definition
| A network sponsored by the National Science Foundation originally intended for universities. |
|
|
Term
|
Definition
| The repetitive unit of a periodic signal. |
|
|
Term
|
Definition
| A linear cod in which the cyclic shifting (rotation) of each codeword creates another code word. |
|
|
Term
| cyclic redundancy check (CRC) |
|
Definition
| A highly accurate error-detection method based on interpreting a pattern of bits as a polynomial. |
|
|
Term
|
Definition
| The FTP connection used for data transfer. |
|
|
Term
|
Definition
| The smallest entity that can represent a piece of information. A bit. |
|
|
Term
| data encryption standard (DES) |
|
Definition
| The U.S. government standard encryption method for nonmilitary and nonclassified use. |
|
|
Term
|
Definition
| A protocol that uses the secret key to encrypt the data for secrecy and to encrypt the message digest for integrity. |
|
|
Term
|
Definition
| The number of different symbols used to represent a digital signal. |
|
|
Term
| data link connection identifier (DLCI) |
|
Definition
| A number that identifies the virtual circuit in Frame Relay. |
|
|
Term
|
Definition
| The responsibilities of the data link layer: flow control and error control. |
|
|
Term
|
Definition
| The second layer in the Internet model. It is responsible for node-to-node delivery. |
|
|
Term
| Data Over Cable System Interface Specifications (DOCSIS) |
|
Definition
| A standard for data transmission over an HFC network. |
|
|
Term
|
Definition
| The number of data elements sent in one second. |
|
|
Term
|
Definition
| The intermediate phase in circuit-switched or virtual-circuit network in which data transfer takes place. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| In packet switching, an independent data unit. |
|
|
Term
| datagram approach (to packet switching) |
|
Definition
| A data transmission method in which each data unit is independent of others. |
|
|
Term
|
Definition
| A packet-switched network in which packets are independent from each other. |
|
|
Term
|
Definition
| A structure designed to be used with a connectionless protocol such as UDP. |
|
|
Term
|
Definition
| The smallest block of data in block coding. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A protocol that has not been approved by an organized body but adopted as a standard through widespread use. |
|
|
Term
|
Definition
| A protocol that has been legislated by an officially recognized body. |
|
|
Term
|
Definition
| A situation in which a task cannot proceed because it is waiting for an even that will never occur. |
|
|
Term
|
Definition
| A measure of the relative strength of two signal points. |
|
|
Term
|
Definition
| Recovery of the original message from the encrypted data. |
|
|
Term
|
Definition
| The mask for a network that is not subnetted. |
|
|
Term
|
Definition
| A routing method in which a router is assigned to receive all packets with no match in the routing table. |
|
|
Term
| Defense Advanced Research Projects Agency (DARPA) |
|
Definition
| A government organization, which, under the name of ARPA funded ARPANET and the Internet. |
|
|
Term
| delayed response strategy |
|
Definition
| A technique used by IGMP to prevent unnecessary traffic on a LAN. |
|
|
Term
|
Definition
| An analog-to-digital conversion technique in which the value of the digital signal is based on the difference between the current and the previous sample values. |
|
|
Term
|
Definition
| The process of separating the carrier signal from the information-bearing signal. |
|
|
Term
|
Definition
| A device that performs demodulation. |
|
|
Term
|
Definition
| A device that separates a multiplexed signal into its original components. |
|
|
Term
|
Definition
| A form of attack in which the site is flooded with so many phony requests that is eventually forced to deny service. |
|
|
Term
| dense wave-division multiplexing (DWDM) |
|
Definition
| A WDM method that can multiplex a very large number of channels by spacing channels closer together. |
|
|
Term
| destination-unreachable message |
|
Definition
| An ICMP error-reporting message sent to a source when a router cannot route a datagram or a host cannot deliver a datagram. |
|
|
Term
|
Definition
| A unit of data consisting of two bits. |
|
|
Term
| differential Manchester encoding |
|
Definition
| A digital-to-digital polar encoding method that features a transition at the middle of the bit interval as well as an inversion at the beginning of each 1 bit. |
|
|
Term
| Differentiated Services (DS or Diffserv) |
|
Definition
| A class-based QoS model designed for IP. |
|
|
Term
|
Definition
| A key management protocol that provides a one-time session key for 2 parties. |
|
|
Term
|
Definition
| A condensed version of a document. |
|
|
Term
|
Definition
| A second-generation cellular phone system that is a digital version of AMPS. |
|
|
Term
|
Definition
| Data represented by discrete values or conditions. |
|
|
Term
| digital data service (DDS) |
|
Definition
| A digital version of an analog leased line with a rate of 64 Kbps. |
|
|
Term
| digital service unit (DSU) |
|
Definition
| A device that allows the connection of a user's device to a digital line. |
|
|
Term
|
Definition
| A discrete signal with a limited number of values. |
|
|
Term
| digital signal (DS) service |
|
Definition
| A telephone company service featuring a hierarchy of digital signals. |
|
|
Term
|
Definition
| A method to authenticate the sender of a message. |
|
|
Term
| digital subscriber line (DSL) |
|
Definition
| A technology using existing telecommunication networks to accomplish high-speed delivery of data, voice, video, and multimedia. |
|
|
Term
| digital subscriber line access multiplexer (DSLAM) |
|
Definition
| A telephone company site device that functions like an ADSL modem. |
|
|
Term
| digital-to-analog conversion |
|
Definition
| The representation of digital information by an analog signal. |
|
|
Term
| digital-to-analog modulation |
|
Definition
| The representation of digital information by an analog signal. |
|
|
Term
| digital-to-digital conversion |
|
Definition
| The representation of digital information by a digital signal. |
|
|
Term
| digital-to-digital encoding |
|
Definition
| The representation of digital information by a digital signal. |
|
|
Term
|
Definition
| Conversion of analog information to digital information. |
|
|
Term
|
Definition
| In link state routing, an algorithm that finds the shortest path to other routers. |
|
|
Term
|
Definition
| A zero-frequency signal with a constant amplitude. |
|
|
Term
|
Definition
| A delivery in which the final destination of the packet is a host connected to the same physical network as the sender. |
|
|
Term
| direct sequence spread spectrum (DSSS) |
|
Definition
| A wireless transmission method in which each bit to be sent by the sender is replaced by a sequence of bits called a chip code. |
|
|
Term
|
Definition
| A bit that defines that a packet can be discarded if there is congestion in the network. |
|
|
Term
| discrete cosine transform (DCT) |
|
Definition
| A JPEG phase in which a transformation changes the 64 values so that the relative relationships between pixels are kept but the redundancies are revealed. |
|
|
Term
| discrete multitone technique (DMT) |
|
Definition
| A modulation method combining elements of QAM and FDM. |
|
|
Term
| Distance Vector Multicast Routing Protocol (DVMRP) |
|
Definition
| A protocol based on distance vector routing that handles multicast routing in conjunction with IGMP. |
|
|
Term
|
Definition
| A routing method in which each router sends its neighbors a list of networks it can reach and the distance to that network. |
|
|
Term
|
Definition
| Any change in a signal due to noise, attenuation, or other influences. |
|
|
Term
| distributed coordination fucntion (DCF) |
|
Definition
| The basic access method in wireless LANs; stations contend with each other to get access to the channel. |
|
|
Term
|
Definition
| Information stored in many locations. |
|
|
Term
| distributed interframe space (DIFS) |
|
Definition
| In wireless LANs, a period of time that a station waits before sending a control frame. |
|
|
Term
|
Definition
| A strategy in which services provided for the network reside at multiple sites. |
|
|
Term
|
Definition
| In an HFC network, a site that modulates and distributes signals. |
|
|
Term
|
Definition
| A computer that holds information about the name space. |
|
|
Term
|
Definition
| A subtree of the domain name space. |
|
|
Term
|
Definition
| In the DNS, a sequence of labels separated by dots. |
|
|
Term
|
Definition
| A structure for organizing the name space in which the names are defined in an inverted-tree structure with the root at the top. |
|
|
Term
|
Definition
| A TCP/IP application service that converts user-friendly names to IP addresses. |
|
|
Term
|
Definition
| A notation devised to make the IP address easier to read; each byte is converted to its decimal equivalent and then set off from its neighbor by a decimal. |
|
|
Term
|
Definition
| Transmission from a satellite to an earth station. |
|
|
Term
|
Definition
| Retrieving a file or data from a remote site. |
|
|
Term
|
Definition
| In an HFC network, the 550 to 750 MHz band for data from the Internet to the subscriber premises. |
|
|
Term
|
Definition
| Two protocols (IPv4 and IPv6) on a station. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A Web document created by running a CGI program at the server site. |
|
|
Term
| Dynamic Domain Name System (DDNS) |
|
Definition
| A method to update the DNS master file dynamically. |
|
|
Term
| Dynamic Host Configuration Protocol (DHCP) |
|
Definition
| An extension to BOOTP that dynamically assigns configuration information. |
|
|
Term
|
Definition
| A technique in which a protocol is used for address resolution. |
|
|
Term
|
Definition
| Routing in which the routing table entries are updated automatically by the routing protocol. |
|
|
Term
|
Definition
| The European equivalent of T lines. |
|
|
Term
| echo-request and reply message |
|
Definition
| An ICMP query message that determines whether two systems (hosts or routers) can communicate with each other. |
|
|
Term
|
Definition
| The bandwidth that the network needs to allocate for the flow of traffic; a function of three values: average data rate, peak data rate, and maximum burst size. |
|
|
Term
|
Definition
| The frequency range occupied by electromagnetic energy. |
|
|
Term
| electronic code block (ECB) mode |
|
Definition
| A DES and triple DES operation method in which a long message is divided into 64-bit blocks before being encrypted separately. |
|
|
Term
|
Definition
| A method of sending messages electronically based on mailbox addresses rather than a direct host-to-host exchange. |
|
|
Term
| Electronics Industries Association (EIA) |
|
Definition
| An organization that promotes electronics manufacturing concerns. It has developed interface standards such as EIA-232, EIA-449, and EIA-530. |
|
|
Term
|
Definition
|
|
Term
| Encapsulating Security Payload (ESP) |
|
Definition
| A protocol defined by IPSec that provides privacy as well as a combination of integrity and message authentication. |
|
|
Term
|
Definition
| The technique in which a data unit from one protocol is placed within the data field portion of the data unit of another protocol. |
|
|
Term
|
Definition
| Converting a message into an unintelligible form that is unreadable unless decrypted. |
|
|
Term
|
Definition
| A switching office that is the terminus for the local loops. |
|
|
Term
|
Definition
| A sender or receiver of data. |
|
|
Term
|
Definition
| A port number used by the client. |
|
|
Term
|
Definition
| The detection and handling of errors in data transmission. |
|
|
Term
| error correction by retransmission |
|
Definition
| The process of correcting bits by resending the data. |
|
|
Term
|
Definition
| An ICMP message sent to the source to report an error. |
|
|
Term
|
Definition
| A station in a wireless LAN that can move from one ESS to another. |
|
|
Term
|
Definition
| In PPP, a state in which communication begins and options are negotiated. |
|
|
Term
|
Definition
| A local area network using CSMA/CD access method. See IEEE Project 802.3. |
|
|
Term
|
Definition
| An error-detection method in which an extra bit is added to the data unit so that the total number of 1s becomes even. |
|
|
Term
|
Definition
| In Frame Relay, the maximum number of bits in excess of Bc that the user can send during a predefined period of time. |
|
|
Term
| Extended Service Set (ESS) |
|
Definition
| A wireless LAN service composed of two or more BSSs with APs as defined by the IEEE 802.11 standard. |
|
|
Term
|
Definition
| Extra headers in the IPv6 datagram that provide additional functionality. |
|
|
Term
|
Definition
| Routing between autonomous systems. |
|
|
Term
|
Definition
| A message that announces all the networks outside the AS. |
|
|
Term
|
Definition
| A private network that uses the TCP/IP protocol suite that allows authorized access from outside users. |
|
|
Term
|
Definition
| Ethernet with a data rate of 100 Mbps. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Retransmission of a segment in TCP protocol when three acknowledgements have been received that imply the loss or corruption of that segment. |
|
|
Term
| Federal Communications Commission (FCC) |
|
Definition
| A government agency that regulates radio, television, and telecommunications. |
|
|
Term
| fiber distributed data interface (FDDI) |
|
Definition
| A high-speed (100-Mbps) LAN, defined by ANSI, using fiber optics, dual ring topology, and the token-passing access method. Today an FDDI network is also used as a MAN. |
|
|
Term
|
Definition
| Ethernet using fiber optic media. |
|
|
Term
|
Definition
| In an HFC network, the location of the optical fiber and coaxial fiber juncture. |
|
|
Term
|
Definition
| A high-bandwidth transmission medium that carries data signals in the form of pulses of light. It consists of a thin cylinder of glass or plastic, called the core, surrounded by a concentric layer of glass or plastic called the cladding. |
|
|
Term
| File Transfer Protocol (FTP) |
|
Definition
| In TCP/IP, an application layer protocol that transfers files between two sites. |
|
|
Term
|
Definition
| A process in which a bridge makes forwarding decisions. |
|
|
Term
|
Definition
| A machine that goes through a limited number of states. |
|
|
Term
|
Definition
| A device (usually a router) installed between the internal network of an organization and the rest of the Internet to provide security. |
|
|
Term
| first-in, first-out (FIFO) queue |
|
Definition
| A queue in which the first item in is the first item out. |
|
|
Term
|
Definition
| A bit pattern or a character added to the beginning and the end of a fame to separate the frames. |
|
|
Term
|
Definition
| In an HDLC frame, an 8-bit synchronization sequence that identifies the beginning or end of a frame. |
|
|
Term
|
Definition
| A method to map a name to an address in which there is no hierarchical structure. |
|
|
Term
|
Definition
| Saturation of a network with a message. |
|
|
Term
|
Definition
| A technique to control the rate of flow of frames (packets or messages). |
|
|
Term
|
Definition
| An IPv6 mechanism to enable the source to request special handling of a packet. |
|
|
Term
|
Definition
| An area on Earth that is covered by a satellite at a specific time. |
|
|
Term
|
Definition
| Correction of errors at the receiver. |
|
|
Term
| forward explicit congestion notification (FECN) |
|
Definition
| A bit in the Frame Relay packet that notifies the destination of congestion. |
|
|
Term
|
Definition
| Placing the packet in its route to its destination. |
|
|
Term
|
Definition
| A port on a bridge that forwards a received frame. |
|
|
Term
|
Definition
| The mathematical technique used to obtain the frequency spectrum of an aperiodic signal if the time-domain representation is given. |
|
|
Term
|
Definition
| The division of a packet into smaller units to accommodate a protocol's MTU. |
|
|
Term
|
Definition
| A field in the IP header used in fragmentation to show the relative position of the fragment with respect to the whole datagram. |
|
|
Term
|
Definition
| A group of bits representing a block of data. |
|
|
Term
|
Definition
| A technique in CSMA/CD Gigabit Ethernet in which multiple frames are logically connected to each other to resemble a longer frame. |
|
|
Term
| frame check sequence (FCS) |
|
Definition
| The HDLC error-detection field containing either a 2- or 4-byte CRC. |
|
|
Term
|
Definition
| A packet-switching specification defined for the first two layers of the Internet model. There is no network layer. Error checking is done on end-to-end basis instead of on each link. |
|
|
Term
| Frame Relay assembler/disassembler (FRAD) |
|
Definition
| A device used in Frame Relay to handle frames coming from other protocols. |
|
|
Term
|
Definition
| A bit used for synchronization purposes in TDM. |
|
|
Term
|
Definition
| The number of cycles per second of a periodic signal. |
|
|
Term
|
Definition
| The number of cycles per second of a periodic signal. |
|
|
Term
| frequency division multiple access (FDMA) |
|
Definition
| A multiple access method in which the bandwidth is divided into channels. |
|
|
Term
| frequency hopping spread spectrum (FHSS) |
|
Definition
| A wireless transmission method in which the sender transmits at one carrier frequency for a short period of time, then hops to another carrier frequency for the same amount of time, hops again for the same amount of time, and so on. After N hops, the cycle is repeated. |
|
|
Term
| frequency modulation (FM) |
|
Definition
| An analog-to-analog modulation method in which the carrier signal's frequency varies with the amplitude of the modulating signal. |
|
|
Term
| frequency shift keying (FSK) |
|
Definition
| A digital-to-analog encoding method in which the frequency of the carrier signal is varied to represent binary 0 or 1. |
|
|
Term
| frequency-division multiple access (FDMA) |
|
Definition
| An access method technique in which multiple sources use assigned bandwidth in a data communication band. |
|
|
Term
| frequency-division multiplexing (FDM) |
|
Definition
| The combining of analog signals into a single signal. |
|
|
Term
|
Definition
| A graphical representation of a signal's frequency components. |
|
|
Term
|
Definition
| A transmission mode in which communication can be two way simultaneously. |
|
|
Term
| full-duplex switched Ethernet |
|
Definition
| Ethernet in which each station, in its own separate collision domain, can both send and receive. |
|
|
Term
| fully qualified domain name (FQDN) |
|
Definition
| A domain name consisting of labels beginning with the host and going back through each level to the root node. |
|
|
Term
|
Definition
| The frequency of the dominant sine wave of a composite signal. |
|
|
Term
|
Definition
| In the H.323 standard, a server on the LAN that plays the role of the registrar server. |
|
|
Term
|
Definition
| A device used to connect two separate networks that use different communication protocols. |
|
|
Term
|
Definition
| A part of an HTTP request or response message that gives general information about the message. |
|
|
Term
|
Definition
| A subdomain in the domain name system that uses generic suffixes. |
|
|
Term
|
Definition
| A routing technique in which the entire address space is divided into blocks based on physical landmasses. |
|
|
Term
| geosynchronous Earth orbit |
|
Definition
| An orbit that allows a satellite to remain fixed above a certain spot on earth. |
|
|
Term
|
Definition
| Ethernet with a 1000 Mbps data rate. |
|
|
Term
| gigabit medium independent interface (GMII) |
|
Definition
| In Gigabit Ethernet, a specification that defines how the reconciliation sublayer is to be connected to the transceiver. |
|
|
Term
|
Definition
|
|
Term
| Global Positioning System (GPS) |
|
Definition
| An MEO public satellite system consisting of 24 satellites and used for land and sea navigation. GPS is not used for communications. |
|
|
Term
| Global System for Mobile Communication (GSM) |
|
Definition
| A second-generation cellular phone system used in Europe. |
|
|
Term
|
Definition
| An LEO satellite system with 48 satellites in six polar orbits with each orbit hosting eight satellites. |
|
|
Term
|
Definition
| An error-control method in which the frame in error and all following frames must be retransmitted. |
|
|
Term
|
Definition
| Resumption of multicast messages. |
|
|
Term
|
Definition
| Propagation of radio waves through the lowest portion of the atmosphere (hugging the earth). |
|
|
Term
|
Definition
| An analog signal created by 12 voice channels multiplexed together. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A multicast routing feature in which each group in the system shares the same tree. |
|
|
Term
|
Definition
| A bandwidth separating two signals. |
|
|
Term
|
Definition
| Transmission media with a physical boundary. |
|
|
Term
|
Definition
| A standard designed by ITU to allow telephones on the public telephone network to talk to computers (called terminals in H.323) connected to the Internet. |
|
|
Term
|
Definition
| A transmission mode in which communication can be two-way but not at the same time. |
|
|
Term
|
Definition
| A method that adds redundant bits to a data unit to detect and correct bit errors. |
|
|
Term
|
Definition
| The number of differences between the corresponding bits in two datawords. |
|
|
Term
|
Definition
| Changing to a new channel as a mobile device moves from one cell to another. |
|
|
Term
|
Definition
| A protocol to establish or terminate a connection. |
|
|
Term
|
Definition
| Components of a digital signal, each having a different amplitude, frequency, and phase. |
|
|
Term
|
Definition
| An algorithm that creates a fixed-size digest from a variable-length message. |
|
|
Term
| hashed-message authentication code (HMAC) |
|
Definition
| A MAC based on a keyless hash function such as SHA-1. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Control information added to the beginning of a data packet. Also, in an email, the part of the message that defines the sender, the receiver, the subject of the message, and other information. |
|
|
Term
|
Definition
| Conversion of the IPv6 header to IPv4. |
|
|
Term
|
Definition
| Unit of measurement for frequency. |
|
|
Term
| hexadecimal colon notation |
|
Definition
| In IPv6, an address notation consisting of 32 hexadecimal digits, with every four digits separated by a colon. |
|
|
Term
|
Definition
| A name space made of several parts, with each succeeding part becoming more and more specific. |
|
|
Term
|
Definition
| A routing technique in which the entire address space is divided into levels based on specific criteria. |
|
|
Term
| high bit rate digital subscriber line (HDSL) |
|
Definition
| A service similar to the T1-line that can operate at lengths up to 3.6 km. |
|
|
Term
| High Rate Direct Sequence Spread Spectrum (HR-DSSS) |
|
Definition
| A signal generation method similar to DSSS except for the encoding method (CCK). |
|
|
Term
| High-level Data Link Control (HDLC) |
|
Definition
| A bit-oriented data link protocol defined by the ISO. It is used in X.25 protocol. A subset, called link access procedure (LAP), is used in other protocols. It is also a base for many data link protocols used in LANs. |
|
|
Term
|
Definition
| A unit of hypertext or hypermedia available on the Web that is the main page for an organization or an individual. |
|
|
Term
|
Definition
| The number of nodes along a route. It is a measurement of distance in routing algorithms. |
|
|
Term
|
Definition
| An IPv6 field that limits the number of routers that a packet can visit. |
|
|
Term
|
Definition
| Transmission of frames from one node to the next. |
|
|
Term
|
Definition
| A scoop-shaped antenna used in terrestrial microwave communication. |
|
|
Term
|
Definition
| A station or node on a network. |
|
|
Term
|
Definition
| A file, used when the Internet was small, that mapped host names to host addresses. |
|
|
Term
|
Definition
| The part of an IP address that identifies a host. |
|
|
Term
|
Definition
| A routing method in which the full IP address of a host is given in the routing table. |
|
|
Term
|
Definition
| A central device in a star topology that provides a common connection among the nodes. |
|
|
Term
|
Definition
| A statistical compression method using variable-length codes to encode a set of symbols. |
|
|
Term
|
Definition
| A network with a private internet and access to the global Internet. |
|
|
Term
| hybrid-fiber-coaxial (HFC) network |
|
Definition
| The second generation of cable networks; uses fiber optic and coaxial cable. |
|
|
Term
|
Definition
| Information containing text, pictures, graphics, and sound that are linked to other documents through pointers. |
|
|
Term
|
Definition
| Information containing text that is linked to other documents through pointers. |
|
|
Term
| HyperText Markup Language (HTML) |
|
Definition
| The computer language for specifying the contents and format of a web document. It allows additional text to include codes that define fonts, layouts, embedded graphics, and hypertext links. |
|
|
Term
| HyperText Transfer Protocol (HTTP) |
|
Definition
| An application service for retrieving a web document. |
|
|
Term
|
Definition
| In PPP, a state in which the link is inactive. |
|
|
Term
|
Definition
| In FTP, the default format for transferring binary files. The file is sent as continuous streams of bits without any interpretation or encoding. |
|
|
Term
| incumbent local exchange carrier (ILEC) |
|
Definition
| A telephone company that provided services before 1996 and is the owner of the cabling system. |
|
|
Term
|
Definition
| A delivery in which the source and destination of a packet are in different networks. |
|
|
Term
|
Definition
| A wave with a frequency between 300 GHz and 400 THz; usually used for short-range communications. |
|
|
Term
|
Definition
| A number produced by multiplying two sequences, element by element, and summing the products. |
|
|
Term
| Institute of Electrical and Electronics Engineers (IEEE) |
|
Definition
| A group consisting of professional engineers which has specialized societies whose committees prepare standards in members' areas of specialty. |
|
|
Term
| Integrated Services (IntServ) |
|
Definition
| A flow-based QoS model designed for IP. |
|
|
Term
|
Definition
| A data quality of being noncorrupted. |
|
|
Term
|
Definition
| Real-time communication with sound and images. |
|
|
Term
| interautonomous system routing protocol |
|
Definition
| A protocol to handle transmissions between autonomous systems. |
|
|
Term
|
Definition
| Routing among autonomous systems. |
|
|
Term
| interexchange carrier (IXC) |
|
Definition
| A long-distance company that, prior to the Act of 1996, provided communication services between two customers in different LATAs. |
|
|
Term
|
Definition
| The boundary between two pieces of equipment. It also refers to mechanical, electrical, and functional characteristics of the connection. |
|
|
Term
|
Definition
| Any undesired energy that interferes with the desired signals. |
|
|
Term
|
Definition
| In wireless LANs, a time interval between two frames to control access to the channel. |
|
|
Term
| Interim Standard 95 (IS-95) |
|
Definition
| One of the dominant second-generation cellular telephony standards in North America. |
|
|
Term
|
Definition
| Routing inside an autonomous system. |
|
|
Term
|
Definition
| Taking a specific amount of data from each device in a regular order. |
|
|
Term
| International Organization of Standardization (ISO) |
|
Definition
| A worldwide organization that defines and develops standards on a variety of topics. |
|
|
Term
| International Telecommunications Union-Telecommunication Standardization Sector (ITU-T) |
|
Definition
| A standards organization formerly known as the CCITT. |
|
|
Term
|
Definition
| A collection of networks connected by internetworking devices such as routers or gateways. |
|
|
Term
|
Definition
| A global internet that uses the TCP/IP protocol suite. |
|
|
Term
|
Definition
| A 32-bit or 128-bit network-layer address used to uniquely define a host on an internet using the TCP/IP protocol. |
|
|
Term
| Internet Architecture Board (IAB) |
|
Definition
| The technical adviser to the ISOC; oversees the continuing development of the TCP/IP protocol suite. |
|
|
Term
| Internet Assigned Numbers Authority (IANA) |
|
Definition
| A group supported by the U.S. government that was responsible for the management of Internet domain names and addresses until October 1998. |
|
|
Term
| Internet Control Message Protocol (ICMP) |
|
Definition
| A protocol in the TCP/IP protocol suite that handles error and control messages. |
|
|
Term
| Internet Control Message Protocol, version 6 (ICMPv6) |
|
Definition
| A protocol in IPv6 that handles error and control messages. |
|
|
Term
| Internet Corporation for Assigned Names and Numbers (ICANN) |
|
Definition
| A private, nonprofit corporation managed by an international board that assumed IANA operations. |
|
|
Term
|
Definition
| A working Internet document (a work in progress) with no official status and a six-month lifetime. |
|
|
Term
| Internet Engineering Steering Group (IESG) |
|
Definition
| An organization that oversees the activity of IETF. |
|
|
Term
| Internet Engineering Task Force (IETF) |
|
Definition
| A group working on the design and development of the TCP/IP protocol suite and the Internet. |
|
|
Term
| Internet Group Management Protocol (IGMP) |
|
Definition
| A protocol in the TCP/IP protocol suite that handles multicasting. |
|
|
Term
| Internet Key Exchange (IKE) |
|
Definition
| A protocol designed to create security associations in SADBs. |
|
|
Term
| Internet Mail Access Protocol, version 4 (IMAP4) |
|
Definition
| A complex and powerful protocol to handle the transmission of electronic mail. |
|
|
Term
| Internet Mobile Communication for year 2000 (ITM-2000) |
|
Definition
| An ITU issued blueprint that defines criteria for third generation cellular telephony. |
|
|
Term
|
Definition
| A 5-layer protocol stack that dominates data communications and networking today. |
|
|
Term
| Internet Network Information Center (INTERNIC) |
|
Definition
| An agency responsible for collecting and distributing information about TCP/IP protocols. |
|
|
Term
|
Definition
| The network-layer protocol in the TCP/IP protocol suite governing connectionless transmission across packet switching networks. |
|
|
Term
| Internet Protocol next generation (IPng) |
|
Definition
| See Internet Protocol version 6 (IPv6). |
|
|
Term
| Internet Protocol version 4 (IPv4) |
|
Definition
| The current version of Internet Protocol. |
|
|
Term
| Internet Protocol, version 6 (IPv6) |
|
Definition
| The sixth version of the Internetworking Protocol; it features major IP addressing changes. |
|
|
Term
| Internet Research Task Force (IRTF) |
|
Definition
| A forum of working groups focusing on long-term research topics related to the Internet. |
|
|
Term
| Internet Security Association and Key Management Protocol (ISAKMP) |
|
Definition
| A protocol designed by the national Security Agency (NSA) that actually implements the exchanges defined in IKE. |
|
|
Term
| Internet service provider (ISP) |
|
Definition
| Usually, a company that provides Internet services. |
|
|
Term
|
Definition
| The nonprofit organization established to publicize the Internet. |
|
|
Term
|
Definition
| A thoroughly tested specification that is useful to and adhered to by those who work with the Internet. It is a formalized regulation that must be followed. |
|
|
Term
|
Definition
|
|
Term
| Internetwork Protocol Control Protocol (IPCP) |
|
Definition
| In PPP, the set of protocols that establish and terminate a network layer connection for IP packets. |
|
|
Term
|
Definition
| Connecting several networks together using internetworking devices such as routers and gateways. |
|
|
Term
| intracoded frame (I-frame) |
|
Definition
| An independent frame that is not related to any other frame and appearing at regular intervals. |
|
|
Term
|
Definition
| A private network that uses the TCP/IP protocol suite. |
|
|
Term
|
Definition
| A subdomain in the DNS that finds the domain name given the IP address. |
|
|
Term
|
Definition
| Taking data from one source and breaking it into portions that can be sent across lower-speed lines. |
|
|
Term
|
Definition
| The Internetworking Protocol data unit. |
|
|
Term
|
Definition
| A collection of protocols designed by the IETF (Internet Engineering Task Force) to provide security for a packet carried on the Internet. |
|
|
Term
|
Definition
| A port that allows a wireless keyboard to communicate with a PC. |
|
|
Term
|
Definition
| A 66-satellite network that provides communication from any Earth site to another. |
|
|
Term
|
Definition
| A protocol at the upper layer of SS7 that provides services similar to those of an ISDN network. |
|
|
Term
|
Definition
| A type of transmission in which the entire stream of bits is synchronized under the control of a common clock. |
|
|
Term
|
Definition
| Resolution of the IP address in which the client may send its request to multiple servers before getting an answer. |
|
|
Term
|
Definition
| In the client-server model, a server that can serve only one client at a time. |
|
|
Term
|
Definition
| In CSMA/CD, a signal sent by the first station that detects collision to alert every other station of the situation. |
|
|
Term
|
Definition
| A programming language used to create active Web documents. |
|
|
Term
|
Definition
| A phenomenon in real-time traffic caused by gaps between consecutive packets at the receiver. |
|
|
Term
| Joint Photographic Experts Group (JPEG) |
|
Definition
| A standard for compressing continuous-tone picture. |
|
|
Term
|
Definition
| An analog signal created by six multiplexed master groups. |
|
|
Term
|
Definition
| An algorithm that does not include the retransmitted segments in calculation of round-trip time. |
|
|
Term
|
Definition
| A message that establishes a relationship between the two routers. |
|
|
Term
|
Definition
| A timer that prevents a long idle connection between two TCPs. |
|
|
Term
|
Definition
| An authentication protocol used by Windows 2000. |
|
|
Term
|
Definition
| A number that a cipher operates on. |
|
|
Term
| key distribution center (KDC) |
|
Definition
| In secret key encryption, a trusted third party that shares a key with each user. |
|
|
Term
|
Definition
| Local area network emulation using ATM switches. |
|
|
Term
| LAN emulation client (LEC) |
|
Definition
| In ATM LANs, client software that receives services from a LES. |
|
|
Term
| LAN emulation server (LES) |
|
Definition
| In ATM LANs, server software that creates a virtual circuit between the source and destination. |
|
|
Term
|
Definition
| A model based on ordered tiers. |
|
|
Term
|
Definition
| An algorithm to shape bursty traffic. |
|
|
Term
|
Definition
| An MOSPF feature in which the tree is based on a chosen metric instead of shortest path. |
|
|
Term
|
Definition
| An IGMP message sent by a host when no process is interested in a specific group. |
|
|
Term
|
Definition
| LAN in which ATM technology is used as a backbone to connect traditional LANs. |
|
|
Term
|
Definition
| Converting binary data into signals. |
|
|
Term
|
Definition
| A block code in which adding two codewords creates another codeword. |
|
|
Term
| line-of-sight propagation |
|
Definition
| The transmission of very high frequency signals in straight lines directly from antenna to antenna. |
|
|
Term
|
Definition
| The physical communication pathway that transfers data from one device to another. |
|
|
Term
| Link Control Protocol (LCP) |
|
Definition
| A PPP protocol responsible for establishing, maintaining, configuring, and terminating links. |
|
|
Term
|
Definition
| An OPv6 address used by a private LAN. |
|
|
Term
| link state advertisement (LSA) |
|
Definition
| In OSPF, a method that disperses information. |
|
|
Term
|
Definition
| In link state routing, a database common to all routers and made from LSP information. |
|
|
Term
|
Definition
| In link state routing, a small packet containing routing information sent by a router to all other routers. |
|
|
Term
|
Definition
| A routing method in which each router shares its knowledge of changes in its neighborhood with all other routers. |
|
|
Term
|
Definition
| A packet that provides information about a specific route or routes. |
|
|
Term
|
Definition
| The number of packets sent to a network. |
|
|
Term
|
Definition
| Using a terminal directly connected to the computer. |
|
|
Term
| local access and transport area (LATA) |
|
Definition
| An area covered by one or more telephone companies. |
|
|
Term
|
Definition
| The part of an email address that defines the name of a special file, called the user mailbox, where all of the mail received for a user is stored for retrieval by the user agent. |
|
|
Term
|
Definition
| A network connecting devices inside a single building or inside buildings close to each other. |
|
|
Term
| local area network emulation (LANE) |
|
Definition
| Software that enables an ATM switch to behave like a LAN switch. |
|
|
Term
|
Definition
| A telephone service handling local calls, usually charging a flat monthly fee. |
|
|
Term
| local exchange carrier (LEC) |
|
Definition
| A telephone company that handles services inside a LATA. |
|
|
Term
| local Internet service provider |
|
Definition
| The same as an Internet service provider. |
|
|
Term
|
Definition
| The same as an Internet service provider. |
|
|
Term
|
Definition
| The link that connects a subscriber to the telephone central office. |
|
|
Term
| local management information (LMI) |
|
Definition
| A protocol used in Frame Relay to provide. management features. |
|
|
Term
|
Definition
| An address defined in the network layer. |
|
|
Term
| logical link control (LLC) |
|
Definition
| The upper sublayer of the data link layer as defined by IEEE Project 802.2. |
|
|
Term
| Logical Link Control and Adaptation Protocol (L2CAP) |
|
Definition
| A Bluetooth layer used for data exchange on an ACL link. |
|
|
Term
|
Definition
| The encapsulation of a multicast packet inside a unicast packet to enable multicast routing by non-multicast routers. |
|
|
Term
|
Definition
| The technique in CIDR in which the longest prefix is handled first when searching a routing table. |
|
|
Term
|
Definition
| A polar satellite orbit with an altitude between 500 and 2000 km. A satellite with this orbit has a rotation period of 90 to 120 minutes. |
|
|
Term
|
Definition
| A channel that passes frequencies between 0 and f. |
|
|
Term
| mail transfer agent (MTA) |
|
Definition
| An SMTP component that transfers the mail across the Internet. |
|
|
Term
| management Information Base (MIB) |
|
Definition
| The database used by SNMP that holds the information necessary for management of a network. |
|
|
Term
|
Definition
| A digital-to-digital polar encoding method in which a transition occurs at the middle of each bit interval for the purpose of synchronization. |
|
|
Term
|
Definition
| A key management problem in which an intruder intercepts and sends messages between the intended sender and receiver. |
|
|
Term
|
Definition
| An IPv6 address used when a computer that has migrated to Ipv6 wants to send a packet to a computer still using IPv4. |
|
|
Term
|
Definition
| For IPv4, a 32-bit binary number that gives the first address in the block (the network address) when ANDed with an address in the block. |
|
|
Term
|
Definition
| The one Bluetooth station in a piconet that controls all the others. |
|
|
Term
|
Definition
| An analog signal created by 10 multiplexed supergroups. |
|
|
Term
|
Definition
| The maximum length of time traffic is generated at the peak rate. |
|
|
Term
| maximum transfer unit (MTU) |
|
Definition
| The largest size data unit a specific network can handle. |
|
|
Term
|
Definition
| A help application that plays an audio/video file; used by a browser. |
|
|
Term
|
Definition
| A server accessed by a media player to download an audio/video file. |
|
|
Term
| medium access control (MAC) sublayer |
|
Definition
| The lower sublayer in the data link layer defined by the IEEE 802 project. It defines the access method and access control in different local area network protocols. |
|
|
Term
| medium attachment unit (MAU) |
|
Definition
|
|
Term
|
Definition
| The difference between the highest and lowest frequencies a medium can support. |
|
|
Term
| medium dependent interface (MDI) |
|
Definition
| In Fast Ethernet, implementation-specific hardware that connects the transceiver to the medium. |
|
|
Term
|
Definition
| A satellite orbit positioned between the two Van Allen belts. A satellite at this orbit takes six hours to circle the earth. |
|
|
Term
| medium independent interface (MII) |
|
Definition
| In Fast Ethernet hardware that connects an external transceiver to the reconciliation layer. |
|
|
Term
|
Definition
| An IGMP message sent by a host or router interested in joining a specific group. |
|
|
Term
|
Definition
| A network configuration in which each device has a dedicated point-to-point link to every other device. |
|
|
Term
| message access agent (MAA) |
|
Definition
| A client-server program that pulls the stored email messages. |
|
|
Term
|
Definition
| A security measure in which the sender of the message is verified for every message sent. |
|
|
Term
| message authentication code |
|
Definition
|
|
Term
| message transfer agent (MTA) |
|
Definition
| An SMTP component that transfers the message across the Internet. |
|
|
Term
|
Definition
| A cost assigned for passing through a network. |
|
|
Term
| metropolitan area network (MAN) |
|
Definition
| A network that can span a geographical area the size of a city. |
|
|
Term
|
Definition
| Electromagnetic waves ranging from 2 GHz to 40 GHz. |
|
|
Term
|
Definition
| In a set of words, the smallest Hamming distance between all possible pairs. |
|
|
Term
|
Definition
| In an HFC network, a time slot for timesharing of the upstream channels. |
|
|
Term
|
Definition
| A device that combines real-time signals from different sources into one signal. |
|
|
Term
|
Definition
| A host that can move from one network to another. |
|
|
Term
| mobile switching center (MSC) |
|
Definition
| In cellular telephony, a switching office that coordinates communication between all base stations and the telephone central office. |
|
|
Term
| mobile telephone switching office (MTSO) |
|
Definition
| An office that controls and coordinates communication between all of the cell offices and the telephone control office. |
|
|
Term
|
Definition
| A device consisting of a modulator and a demodulator. It converts a digital signal into an analog signal (modulation) and vice versa (demodulation). |
|
|
Term
| modification detection code (MDC) |
|
Definition
| The digest created by a hash function. |
|
|
Term
|
Definition
| Arithmetic that uses a limited range of integers (O to n-1). |
|
|
Term
|
Definition
| Modification of one or more characteristics of a carrier wave by an information-bearing signal. |
|
|
Term
|
Definition
| A device that converts a digital signal to an analog signal suitable for transmission across a telephone line. |
|
|
Term
|
Definition
| The upper limit in modular arithmetic (n). |
|
|
Term
| monoalphabetic substitution |
|
Definition
| An encryption method in which each occurrence of a character is replaced by another character in the set. |
|
|
Term
| motion picture experts group (MPEG) |
|
Definition
| A method to compress videos. |
|
|
Term
|
Definition
| A fiber-optic cable connector. |
|
|
Term
|
Definition
| An address used for multicasting. |
|
|
Term
| multicast backbone (MBONE) |
|
Definition
| A set of internet routers supporting multicasting through the use of tunneling. |
|
|
Term
| Multicast Open Shortest Path First (MOSPF) |
|
Definition
| A multicast protocol that uses multicast link state routing to create a source-based least cost tree. |
|
|
Term
|
Definition
| A router with a list of loyal members related to each router interface that distributes the multicast packets. |
|
|
Term
|
Definition
| A transmission method that allows copies of a single packet to be sent to a selected group of receivers. |
|
|
Term
|
Definition
| A service provided by SCTP that allows a computer to be connected to different networks. |
|
|
Term
| multiline transmission, 3-level (MLT-3) encoding |
|
Definition
| A line coding scheme featuring 3 levels of signals and transitions at the beginning of the 1 bit. |
|
|
Term
| multimode graded-index fiber |
|
Definition
| An optical fiber with a core having a graded index of refraction. |
|
|
Term
| multimode step-index fiber |
|
Definition
| An optical fiber with a core having a uniform index of refraction. The index of refraction changes suddenly at the core/cladding boundary. |
|
|
Term
|
Definition
| A line access method in which every station can access the line freely. |
|
|
Term
|
Definition
| Sending multiple copies of a message, each with a different unicast address. |
|
|
Term
|
Definition
| A device used for multiplexing. |
|
|
Term
|
Definition
| The process of combining signals from multiple sources for transmission across a single data link. |
|
|
Term
|
Definition
| A congestion avoidance technique in which the threshold is set to half of the last congestion window size, and the congestion window size starts from one again. |
|
|
Term
| Multipurpose Internet Mail Extension (MIME) |
|
Definition
| A supplement to SMTP that allows non-ASCII data to be sent through SMTP. |
|
|
Term
|
Definition
| An array of switches designed to reduce the number of crosspoints. |
|
|
Term
|
Definition
| A service provided by SCTP that allows data transfer to be carried using different streams. |
|
|
Term
|
Definition
| A problem due to the large number of keys needed in symmetric key distribution. |
|
|
Term
|
Definition
| An algorithm that attempts to prevent silly window syndrome at the sender's site; both the rate of data production and the network speed are taken into account. |
|
|
Term
|
Definition
| All the names assigned to machines on an internet. |
|
|
Term
|
Definition
| Mapping a name to an address or an address to a name. |
|
|
Term
| national service provider (NSP) |
|
Definition
| A backbone network created and maintained by a specialized company. |
|
|
Term
| Needham-Schroeder protocol |
|
Definition
| A key management protocol using multiple challenge-response interactions between 2 entities. |
|
|
Term
| negative acknowledgment (NAK) |
|
Definition
| A message sent to indicate the rejection of received data. |
|
|
Term
|
Definition
| The part of an IP address that identifies the network. |
|
|
Term
|
Definition
| A system consisting of connected nodes made to share data, hardware, and software. |
|
|
Term
| network access point (NAP) |
|
Definition
| A complex switching station that connects backbone networks. |
|
|
Term
|
Definition
| An address that identifies a network to the rest of the Internet; it is the first address in a block. |
|
|
Term
| network address translation (NAT) |
|
Definition
| A technology that allows a private network to use a set of private addresses for internal communication and a set of global Internet addresses for external communication. |
|
|
Term
| network allocation vector (NAV) |
|
Definition
| In CSMA/CA, the amount of time that must pass before a station can check the line for idleness. |
|
|
Term
| Network Control Protocol (NCP) |
|
Definition
| In PPP, a set of control protocols that allows the encapsulation of data coming from network layer protocols. |
|
|
Term
| network interface card (NIC) |
|
Definition
| An electronic device, internal or external to a station, that contains circuitry to enable the station to be connected to the network. |
|
|
Term
|
Definition
| The third layer in the Internet model, responsible for the delivery of a packet to the final destination. |
|
|
Term
|
Definition
| An LSA packet that announces the existence of all of the routers connected to the network. |
|
|
Term
| Network Virtual Terminal (NVT) |
|
Definition
| A TCP/IP application protocol that allows remote login. |
|
|
Term
|
Definition
| A PPP state in which packets of user data and packets for control are transmitted. |
|
|
Term
|
Definition
| Routing in which all hosts on a network share one entry in the routing table. |
|
|
Term
| network-to-network interface (NNI) |
|
Definition
| In ATM, the interface between two networks. |
|
|
Term
|
Definition
| In IPv6, an 8-bit field defining the header that follows the base header in the datagram. |
|
|
Term
|
Definition
| A routing method in which only the address of the next hop is listed in the routing table instead of a complete list of the stops the packet must make. |
|
|
Term
|
Definition
| An addressable communication device (e.g., a computer or router) on a network. |
|
|
Term
|
Definition
| Transfer of a data unit from one node to the next. |
|
|
Term
|
Definition
| Random electrical signals that can be picked by the transmission medium and result in degradation or distortion of the data. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A channel that can produce error in data transmission. |
|
|
Term
|
Definition
| A large random number that is used once to distinguish a fresh authentication request from a used one. |
|
|
Term
|
Definition
| A connection in which one TCP connection is made for each request/response. |
|
|
Term
|
Definition
| A random multiple access method in which a station waits a random period of time after a collision is sensed. |
|
|
Term
|
Definition
| A security aspect in which a receiver must be able to prove that a received message came from a specific sender. |
|
|
Term
|
Definition
| A digital-to-digital polar encoding method in which the signal level is always either positive or negative. |
|
|
Term
| nonreturn to zero, invert (NRZ-I) |
|
Definition
| An NRZ encoding method in which the signal level is inverted each time a 1 is encountered. |
|
|
Term
| nonreturn to zero, level (NRZ-L) |
|
Definition
| An NRZ encoding method in which the signal level is directly related to the bit value. |
|
|
Term
| normal response mode (NRM) |
|
Definition
| In HDLC, a communication mode in which the secondary station must have permission from the primary station before transmission can proceed. |
|
|
Term
|
Definition
| A BGP message sent by a router whenever an error condition is detected or a router wants to close the connection. |
|
|
Term
|
Definition
| In wireless LANs, mobility confined inside a BSS or non-mobility. |
|
|
Term
|
Definition
| The data rate based on the Nyquist theorem. |
|
|
Term
|
Definition
| A theorem that states that the number of samples needed to adequately represent an analog signal is equal to twice the highest frequency of the original signal. |
|
|
Term
|
Definition
| A key creating protocol, developed by Hilarie Orman, which is one of the three components of IKE protocol. |
|
|
Term
|
Definition
| An error-detection method in which an extra bit is added to the data unit such that the sum of all 1-bits becomes odd. |
|
|
Term
|
Definition
| An antenna that sends out or receives signals in all directions. |
|
|
Term
|
Definition
| Another name for streaming stored audio/video. |
|
|
Term
|
Definition
| A representation of binary numbers in which the complement of a number is found by complementing all bits. |
|
|
Term
|
Definition
| A BGP message sent by a router to create a neighborhood relationship. |
|
|
Term
| open shortest path first (OSPF) |
|
Definition
| An interior routing protocol based on link state routing. |
|
|
Term
|
Definition
| A model that allows two different systems to communicate regardless of their underlying architecture. |
|
|
Term
| Open Systems Interconnection (OSI) model |
|
Definition
| A seven-layer model for data communication defined by ISO. |
|
|
Term
| open-loop congestion control |
|
Definition
| Policies applied to prevent congestion. |
|
|
Term
|
Definition
| The hierarchy of fiber-optic carriers defined in SONET. The hierarchy defines up to 10 different carriers (OC-1, OC-3, OC-12, . . . , OC-192), each with a different data rate. |
|
|
Term
|
Definition
| A thin thread of glass or other transparent material to carry light beams. |
|
|
Term
|
Definition
| A BGP path attribute that need not be recognized by every router. |
|
|
Term
|
Definition
| The path a satellite travels around the earth. |
|
|
Term
| Orthogonal Frequency Division Multiplexing (OFDM) |
|
Definition
| A multiplexing method similar to FDM, with all the subbands used by one source at a given time. |
|
|
Term
|
Definition
| A sequence with special properties between elements. |
|
|
Term
|
Definition
| A key management protocol with less steps than the Needham-Schroeder method. |
|
|
Term
|
Definition
| Using two separate channels for data and control. |
|
|
Term
| output feedback (OFB) mode |
|
Definition
| A mode similar to the CFB mode with one difference. Each bit in the ciphertext s independent of the previous bit or bits. |
|
|
Term
|
Definition
| Extra bits added to the data unit for control purposes. |
|
|
Term
|
Definition
| Synonym for data unit, mostly used in the network layer. |
|
|
Term
|
Definition
| Data transmission using a packet-switched network. |
|
|
Term
|
Definition
| A firewall that forwards or blocks packets based on the information in the network-layer and transport-layer headers. |
|
|
Term
|
Definition
| A network in which data are transmitted in independent units called packets. |
|
|
Term
|
Definition
| A unit of hypertext or hypermedia available on the Web. |
|
|
Term
|
Definition
| An antenna shaped like a parabola used for terrestrial microwave communication. |
|
|
Term
|
Definition
| Transmission in which bits in a group are sent simultaneously, each using a separate link. |
|
|
Term
| parameter-problem message |
|
Definition
| An ICMP message that notifies a host that there is an ambiguous or missing value in any field of the datagram. |
|
|
Term
|
Definition
| A redundant bit added to a data unit (usually a character) for error checking. |
|
|
Term
|
Definition
| An error-detection method using a parity bit. |
|
|
Term
| partially qualified domain name (PQDN) |
|
Definition
| A domain name that does not include all the levels between the host and the root node. |
|
|
Term
|
Definition
| The state of a server as it waits for incoming requests from a client. |
|
|
Term
| Password Authentication Protocol (PAP) |
|
Definition
| A simple two-step authentication protocol used in PPP. |
|
|
Term
|
Definition
| The channel through which a signal travels. |
|
|
Term
|
Definition
| A SONET layer responsible for the movement of a signal from its optical source to its optical destination. |
|
|
Term
|
Definition
| Control information used by the SONET path layer. |
|
|
Term
|
Definition
| A routing method on which BGP is based; in this method, the ASs through which a packet must pass are explicitly listed. |
|
|
Term
|
Definition
| A hardware circuit used in encryption that connects input to output. |
|
|
Term
|
Definition
| The maximum signal value of a sine wave. |
|
|
Term
|
Definition
| The maximum data rate of the traffic. |
|
|
Term
|
Definition
| A process on a sending and a receiving machine that communicate at a given layer. |
|
|
Term
|
Definition
| In the Diffserv model, a 6-bit field that defines the packet-handling mechanism for the packet. |
|
|
Term
|
Definition
| The amount of time required to complete one full cycle. |
|
|
Term
|
Definition
| A signal that exhibits a repeating pattern. |
|
|
Term
| permanent virtual circuit (PVC) |
|
Definition
| A virtual circuit transmission method in which the same virtual circuit is used between source and destination on a continual basis. |
|
|
Term
|
Definition
| A technique to handle the zero window-size advertisement. |
|
|
Term
|
Definition
| A connection in which the server leaves the connection open for more requests after sending a response. |
|
|
Term
|
Definition
| In CSMA, a strategy in which the station sends a frame after sensing the line. |
|
|
Term
| Personal Communication System (PCS) |
|
Definition
| A generic term for a commercial cellular system that offers several kinds of communication services. |
|
|
Term
|
Definition
| The relative position of a signal in time. |
|
|
Term
|
Definition
| An analog-to-analog modulation method in which the carrier signal's phase varies with the amplitude of the modulating signal. |
|
|
Term
|
Definition
| A digital-to-analog modulation method in which the phase of the carrier signal is varied to represent a specific bit pattern. |
|
|
Term
|
Definition
| The transceiver in Fast Ethernet. |
|
|
Term
|
Definition
| The address of a device used at the data link layer (MAC address). |
|
|
Term
|
Definition
| The first layer of the Internet model, responsible for the mechanical and electrical specifications of the medium. |
|
|
Term
| physical layer signaling (PLS) sublayer |
|
Definition
| An Ethernet sublayer that encodes and decodes data. |
|
|
Term
|
Definition
| The manner in which devices are connected in a network. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| The inclusion of acknowledgment on a data frame. |
|
|
Term
|
Definition
| In Go-Back-n ARQ, sending several frames before news is received concerning previous frames. |
|
|
Term
|
Definition
| A picture element of an image. |
|
|
Term
| plain old telephone system (POTS) |
|
Definition
| The conventional telephone network used for voice communication. |
|
|
Term
|
Definition
| In encryption/decryption, the original message. |
|
|
Term
|
Definition
| A buffer that stores the data until they are ready to be played. |
|
|
Term
| point coordination function (PCF) |
|
Definition
| In wireless LANs, an optional and complex access method implemented in an infrastructure network. |
|
|
Term
|
Definition
| A switching office where carriers can interact with each other. |
|
|
Term
|
Definition
| See point-to-point connection. |
|
|
Term
| point-to-point connection |
|
Definition
| A dedicated transmission link between two devices. |
|
|
Term
|
Definition
| A dedicated transmission link between two devices. |
|
|
Term
| Point-to-Point Protocol (PPP) |
|
Definition
| A protocol for data transfer across a serial line. |
|
|
Term
|
Definition
| A feature added to split horizon in which a table entry that has come through on interface is set to infinity in the update packet. |
|
|
Term
|
Definition
| A digital-to-analog encoding method that uses two levels (positive and negative) of amplitude. |
|
|
Term
|
Definition
| A path vector routing feature in which the routing tables are based on rules set by the network administrator rather than a metric. |
|
|
Term
|
Definition
| In the primary/secondary access method, a procedure in which the primary station asks a secondary station if it has any data to transmit. |
|
|
Term
|
Definition
| A bit in the control field of HDLC; if the primary is sending, it can be a poll bit; if the secondary is sending, it can be a final bit. |
|
|
Term
|
Definition
| An access method protocol using poll and select procedures. See poll. See select. |
|
|
Term
|
Definition
| An access method in which one device is designated as a primary station and the others as the secondary stations. The access is controlled by the primary station. |
|
|
Term
| polyalphabetic substitution |
|
Definition
| An encryption method in which each occurrence of a character can have a different substitute. |
|
|
Term
|
Definition
| An algebraic term that can represent a CRC divisor. |
|
|
Term
|
Definition
| In a URL, the port number of the server. |
|
|
Term
|
Definition
| In TCP/IP protocol an integer identifying a process. |
|
|
Term
|
Definition
| An integer that defines a process running on a host. |
|
|
Term
| Post Office Protocol, version 3 (POP3) |
|
Definition
| A popular but simple SMTP mail access protocol. |
|
|
Term
|
Definition
| A CSMA persistence strategy in which a station sends with probablity p if it finds the line idle. |
|
|
Term
|
Definition
| A CSMA persistence strategy in which a station sends with probability p if it finds the line idle. |
|
|
Term
|
Definition
| The 7-byte field of an IEEE 802.3 frame consisting of alternating 1s and 0s that alert and synchronize the receiver. |
|
|
Term
| predicted frame (P-frame) |
|
Definition
| An MPEG frame which contains only the changes from the preceding frame. |
|
|
Term
|
Definition
| In audio compression, encoding only the differences between the samples. |
|
|
Term
|
Definition
| The common part of an address range. |
|
|
Term
|
Definition
| The sixth layer of the OSI model responsible for translation, encryption, authentication, and data compression. |
|
|
Term
| Pretty Good Privacy (PGP) |
|
Definition
| A protocol that provides all four aspects of security in the sending of email. |
|
|
Term
|
Definition
| A server that stores a file about the zone for which it is an authority. |
|
|
Term
|
Definition
| In primary/secondary access method, a station that issues commands to the secondary stations. |
|
|
Term
|
Definition
| A queuing technique in which packets are assigned to a priority class, each with its own queue. |
|
|
Term
|
Definition
| A security aspect in which the message makes sense only to the intended receiver. |
|
|
Term
|
Definition
| In conventional encryption, a key shared by only one pair of devices, a sender and a receiver. In public-key encryption, the private key is known only to the receiver. |
|
|
Term
|
Definition
| A network that is isolated from the Internet. |
|
|
Term
|
Definition
| A running application program. |
|
|
Term
| process-to-process delivery |
|
Definition
| Delivery of a packet from the sending process to the destination process. |
|
|
Term
|
Definition
| A combination of P-boxes and S-boxes to get a more complex cipher block. |
|
|
Term
|
Definition
| The project undertaken by the IEEE in an attempt to solve LAN incompatibility. See also IEEE Project 802. |
|
|
Term
|
Definition
| The rate at which a signal or bit travels; measured by distance/second. |
|
|
Term
|
Definition
| The time required for a signal to travel from one point to another. |
|
|
Term
|
Definition
|
|
Term
| Protocol Independent Multicast (PIM) |
|
Definition
| A multicasting protocol family with two members, PIM-DM and PIM-SM; both protocols are unicast-protocol dependent. |
|
|
Term
| Protocol Independent Multicast, Dense Mode (PIM-DM) |
|
Definition
| A source-based routing protocol that uses RPF and pruning/grafting strategies to handle multicasting. |
|
|
Term
| Protocol Independent Multicast, Sparse Mode (PIM-SM) |
|
Definition
| A group-shared routing protocol that is similar to CBT and uses a rendezvous point as the source of the tree. |
|
|
Term
|
Definition
| A stack or family of protocols defined for a complex communication system. |
|
|
Term
|
Definition
| A technique that creates a subnetting effect; on server answers ARP requests for multiple hosts. |
|
|
Term
|
Definition
| A firewall that filters a message based on the information available in the message itself (at the application layer). |
|
|
Term
|
Definition
| A computer that keeps copies of responses to recent requests. |
|
|
Term
|
Definition
| Stopping the sending of multicast messages from an interface. |
|
|
Term
|
Definition
| Information from the IP header used only for checksum calculation in UDP and TCP packet. |
|
|
Term
|
Definition
| A pseudorandom code generator used in FHSS. |
|
|
Term
|
Definition
| In public-key encryption, a key known to everyone. |
|
|
Term
| public key infrastructure (PKI) |
|
Definition
| A hierarchical structure of CA servers. |
|
|
Term
|
Definition
| A method of encryption based on a nonreversible encryption algorithm. The method uses two types of keys: The public key is known to the public; the private key (secret key) is known only to the receiver. |
|
|
Term
| pulse amplitude modulation (PAM) |
|
Definition
| A technique in which an analog signal is sampled; the result is a series of pulses based on the sampled data. |
|
|
Term
| pulse code modulation (PCM) |
|
Definition
| A technique that modifies PAM pulses to create a digital signal. |
|
|
Term
|
Definition
| The number of symbols per second. |
|
|
Term
|
Definition
| In TDM, a technique that adds dummy bits to the input lines with lower rates. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A unit of data consisting of four bits. |
|
|
Term
| quadrature amplitude modulation (QAM) |
|
Definition
| A digital-to-analog modulation method in which the phase and amplitude of the carrier signal vary with the modulating signal. |
|
|
Term
|
Definition
| A set of attributes related to the performance of the connection. |
|
|
Term
|
Definition
| The assignment of a specific range of values to signal amplitudes. |
|
|
Term
|
Definition
| An ICMP message that helps a host or a network manager get specific information from a router or another host. Or, an IGMP message that requests group information from a router or a host. Or, a DNS message that requests information. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Electromagnetic energy in the 3-KHz to 300-GHz range. |
|
|
Term
|
Definition
| A medium access category in which each station can access the medium without being controlled by any other station. |
|
|
Term
|
Definition
| In an HFC network, a process that determines the distance between the CM and the CMTS. |
|
|
Term
| rate adaptive asymmetrical digital subscriber line (RADSL) |
|
Definition
| A DSL-based technology that features different data rates depending on the type of communication. |
|
|
Term
|
Definition
| A structure designed for protocols that directly use the services of IP and use neither stream sockets nor datagram sockets. |
|
|
Term
|
Definition
| Permanent memory with contents that cannot be changed. |
|
|
Term
| Real-Time Streaming Protocol (RTSP) |
|
Definition
| An out-of-band control protocol designed to add more functionality to the streaming audio/video process. |
|
|
Term
| Real-time Transport Control Protocol (RTCP) |
|
Definition
| A companion protocol to RTP with messages that control the flow and quality of data and allow the recipient to send feedback to the source or sources. |
|
|
Term
| Real-time Transport Protocol (RTP) |
|
Definition
| A protocol for real-time traffic; used in conjunction with UDP. |
|
|
Term
|
Definition
| In the TCP sliding window protocol, the window at the receiver site. |
|
|
Term
|
Definition
| A Fast Ethernet sublayer which passes data in 4-bit format to the MII. |
|
|
Term
|
Definition
| Resolution of the IP address in which the client sends its request to a server that eventually returns a response. |
|
|
Term
|
Definition
| An ICMP message type that informs the sender of a preferred route. |
|
|
Term
|
Definition
| The addition of bits to a message for error control. |
|
|
Term
|
Definition
| A complex, but efficient, cyclic code. |
|
|
Term
|
Definition
| The phenomenon related to the bouncing back of light at the boundary of two media. |
|
|
Term
|
Definition
| The phenomenon related to the bending of light when it passes from one medium to another. |
|
|
Term
|
Definition
| A device that regenerates the original signal from a corrupted signal. See also repeater. |
|
|
Term
| regional cable head (RCH) |
|
Definition
| In an HFC network, the main distribution site. |
|
|
Term
|
Definition
| A small ISP that is connected to one or more NSPs. |
|
|
Term
|
Definition
| An authority to register new domain names. |
|
|
Term
|
Definition
| In SIP, a server that knows the IP address of the callee. |
|
|
Term
|
Definition
| A QoS flow characteristic; dependability of the transmission. |
|
|
Term
|
Definition
| Using a terminal that is not directly connected to a computer. |
|
|
Term
|
Definition
| A device that connects LANs and point-to-point networks; often used in a backbone network. |
|
|
Term
|
Definition
| The computer that a user wishes to access while seated physically at another computer. |
|
|
Term
|
Definition
| A program run at a site physically removed from the user. |
|
|
Term
|
Definition
| A router that is the core or center for each multicast group; it becomes the root of the tree. |
|
|
Term
|
Definition
| A group-shared tree method in which there is one tree for each group. |
|
|
Term
|
Definition
| A device that extends the distance a signal can travel by regenerating the signal. |
|
|
Term
|
Definition
| The resending of a message that has been intercepted by an intruder. |
|
|
Term
| Request for Comment (RFC) |
|
Definition
| A formal Internet document concerning an Internet issue. |
|
|
Term
|
Definition
| A part of the HTTP request message that specifies the client's configuration and the client's preferred document format. |
|
|
Term
|
Definition
| The DNS client that is used by a host that needs to map an address to a name or a name to an address. |
|
|
Term
| Resource Reservation Protocol (RSVP) |
|
Definition
| A signaling protocol to help IP create a flow and make a resource reservation to improve QoS. |
|
|
Term
|
Definition
| A part of the HTTP response message that specifies the server's configuration and special information about the request. |
|
|
Term
|
Definition
| A DNS message type that returns information. |
|
|
Term
|
Definition
| The expiration of a timer that controls the retransmission of packets. |
|
|
Term
|
Definition
| A timer that controls the waiting time for an acknowledgment of a segment. |
|
|
Term
|
Definition
| A digital-to-digital encoding technique in which the voltage of the signal is zero for the second half of the bit interval. |
|
|
Term
|
Definition
| In cellular telephony, the number of cells with a different set of frequencies. |
|
|
Term
| Reverse Address Resolution Protocol (RARP) |
|
Definition
| A TCP/IP protocol that allows a host to find its Internet address given its physical address. |
|
|
Term
| reverse path broadcasting (RPB) |
|
Definition
| A technique in which the router forwards only the packets that have traveled the shortest path from the source to the router. |
|
|
Term
| reverse path forwarding (RPF) |
|
Definition
| A technique in which the router forwards only the packets that have traveled the shortest path from the source to the router. |
|
|
Term
| reverse path multicasting (RPM) |
|
Definition
| A technique that adds pruning and grafting to RPB to create a multicast shortest path tree that supports dynamic membership changes. |
|
|
Term
|
Definition
| An algorithm named after its two Belgian inventors, Vincent Rijmen and Joan Daemen that is the basis of AES. |
|
|
Term
|
Definition
| A topology in which the devices are connected in a ring. Each device on the ring receives the data unit from the previous device, regenerates it, and forwards it to the next device. |
|
|
Term
| Rivest, Shamir, Adleman (RSA) encryption |
|
Definition
|
|
Term
|
Definition
| A coaxial cable connector. |
|
|
Term
|
Definition
| In cellular telephony, the ability of a user to communicate outside of his own service provider's area. |
|
|
Term
|
Definition
| In DNS, a server whose zone consists of the whole tree. A root server usually does not store any information about domains but delegates its authority to other servers, keeping references to those servers. |
|
|
Term
|
Definition
| Accessing the switching station through a phone that sends a digital signal to the end office. |
|
|
Term
|
Definition
| A keyed or keyless cipher in which the input bits are rotated to the left or right to create output bits. |
|
|
Term
|
Definition
| The time required for a datagram to go from a source to a destination and then back again. |
|
|
Term
|
Definition
| A path traveled by a packet. |
|
|
Term
|
Definition
| An internetworking device operating at the first three OSI layers. A router is attached to two or more networks and forwards packets from one network to another. |
|
|
Term
|
Definition
| An LSA packet that advertises all of the links of a router. |
|
|
Term
| router-solicitation and advertisement message |
|
Definition
| An ICMP message sent to obtain and disperse router information. |
|
|
Term
|
Definition
| The process performed by a router; finding the next hop for a datagram. |
|
|
Term
| Routing Information Protocol (RIP) |
|
Definition
| A routing protocol based on the distance vector routing algorithm. |
|
|
Term
|
Definition
| A table containing information a router needs to route packets. The information may include the network address, the cost, the address of the next hop, and so on. |
|
|
Term
|
Definition
| A popular public-key encryption method developed by Rivest, Shamir, and Adleman. |
|
|
Term
|
Definition
| The process of obtaining amplitudes of a signal at regular intervals. |
|
|
Term
|
Definition
| The number of samples obtained per second in the sampling process. |
|
|
Term
|
Definition
| A combination of nodes that provides communication form one point on the earth to another. |
|
|
Term
|
Definition
| An encryption device made of decoders, P-boxes, and encoders. |
|
|
Term
|
Definition
| A combination of piconets. |
|
|
Term
|
Definition
| In digital-to-digital conversion, modifying part of the rules in line coding scheme to create bit synchronization. |
|
|
Term
|
Definition
| A rule for finding the next hop. |
|
|
Term
|
Definition
| In DNS, a server that transfers the complete information about a zone from another server (primary or secondary) and stores the file on its local disk. |
|
|
Term
|
Definition
| In poll/select access method, a station that sends a response in answer to a command from a primary station. |
|
|
Term
|
Definition
| A security method in which the key for encryption is the same as the key for decryption; both sender and receiver have the same key. |
|
|
Term
| Secure Hash Algorithm 1 (SHA-1) |
|
Definition
| A hash algorithm designed by the National Institute of Standards and Technology (NIST). It was published as a Federal Information Processing Standard (FIPS). |
|
|
Term
| Secure Socket Layer (SSL) |
|
Definition
| A protocol designed to provide security and compression services to data generated from the application layer. |
|
|
Term
|
Definition
| The protection of a network from unauthorized access, viruses, and catastrophe. |
|
|
Term
| Security Association (SA) |
|
Definition
| An IPSec signaling protocol that creates a logical connection between 2 hosts. |
|
|
Term
| Security association database (SADB) |
|
Definition
| A database defining a set of single security associations. |
|
|
Term
| security parameter index (SPI) |
|
Definition
| A parameter that uniquely distinguish on security association from the others. |
|
|
Term
|
Definition
| The packet at the TCP layer. Also, the length of transmission medium shared by devices. |
|
|
Term
|
Definition
| The splitting of a message into multiple packets; usually performed at the transport layer. |
|
|
Term
| segmentation and reassembly (SAR) |
|
Definition
| The lower AAL sublayer in the ATM protocol in which a header and/or trailer may be added to produce a 48-byte element. |
|
|
Term
|
Definition
| In poll/select access method, a procedure in which the primary station asks a secondary station if it is ready to receive data. |
|
|
Term
|
Definition
| An error-control method in which only the frame in error is resent. |
|
|
Term
|
Definition
| Synchronization of long strings of 1s or 0s through the coding method. |
|
|
Term
|
Definition
| The meaning of each section of bits. |
|
|
Term
|
Definition
| In the TCP sliding window protocol, the window at the sender site. |
|
|
Term
|
Definition
| The number that denotes the location of a frame or packet in a message. |
|
|
Term
|
Definition
| Transmission of data one bit at a time using only one single link. |
|
|
Term
|
Definition
| A program that can provide services to other programs, called clients. |
|
|
Term
| server control point (SCP) |
|
Definition
| In SS7 terminology, the node that controls the whole operation of the network. |
|
|
Term
|
Definition
|
|
Term
| Session Initiation Protocol (SIP) |
|
Definition
| In voice over IP, an application protocol that establishes, manages, and terminates a multimedia session. |
|
|
Term
|
Definition
| The fifth layer of the OSI model, responsible for the establishment, management, and termination of logical connections between two end users. |
|
|
Term
|
Definition
| In virtual circuit switching, a phase in which the source and destination use their global addresses to help switches make table entries for the connection. |
|
|
Term
|
Definition
| An HDLC frame used for supervisory functions such as acknowledgment, flow control, and error control; it contains no user data. |
|
|
Term
|
Definition
| The theoretical highest data rate for a channel. |
|
|
Term
| shielded twisted-pair (STP) |
|
Definition
| Twisted-pair cable enclosed in a foil or mesh shield that protects against electromagnetic interference. |
|
|
Term
|
Definition
| The simplest monoalphabetic cipher in which the plaintext and ciphertext consist of letters. In the encryption algorithm, the characters are shifted down the character list; in the decryption algorithm, the characters are shifted up the character list. |
|
|
Term
|
Definition
| A register in which each memory location, at a time click, accepts the bit at its input port, stores the new bit, and displays it on the output port. |
|
|
Term
| short interframe space (SIFS) |
|
Definition
| In CSMA/CA, a period of time that the destination waits after receiving the RTS. |
|
|
Term
|
Definition
| A routing table formed by using the Dijkstra algorithm. |
|
|
Term
|
Definition
| Electromagnetic waves propagated along a transmission medium. |
|
|
Term
|
Definition
| The shortest section of a signal (time-wise) that represents a data element. |
|
|
Term
|
Definition
| The number of values allowed in a particular signal. |
|
|
Term
|
Definition
| In SS7 terminology, the user telephone or computer is connected to the signal points. |
|
|
Term
|
Definition
| The number of signal elements sent in one second. |
|
|
Term
| Signal transport port (STP) |
|
Definition
| In SS7 terminology, the node used by the signaling network. |
|
|
Term
| signaling connection control point (SCCP) |
|
Definition
| In SS7, the control points used for special services such as 800 calls. |
|
|
Term
| Signaling System Seven (SS7) |
|
Definition
| The protocol that is used in the signaling network. |
|
|
Term
| signal-to-noise ratio (SNR) |
|
Definition
| The signal strength divided by the noise, both in decibels. |
|
|
Term
|
Definition
| A situation in which a small window size is advertised by the receiver and a small segment sent by the sender. |
|
|
Term
| simple and efficient adaptation layer (SEAL) |
|
Definition
| An AAL layer designed for the Internet (AAL5). |
|
|
Term
|
Definition
| A networking device that links two segments; requires manual maintenance and updating. |
|
|
Term
| Simple Mail Transfer Protocol (SMTP) |
|
Definition
| The TCP/IP protocol defining electronic mail service on the Internet. |
|
|
Term
| Simple Network Management Protocol (SNMP) |
|
Definition
| The TCP/IP protocol that specifies the process of management in the Internet. |
|
|
Term
|
Definition
| The simple protocol we used to show an access method without flow and error control. |
|
|
Term
|
Definition
| A transmission mode in which communication is one way. |
|
|
Term
|
Definition
| An amplitude-versus-time representation of a rotating vector. |
|
|
Term
|
Definition
| Error in a data unit in which only one single bit has been altered. |
|
|
Term
|
Definition
| An optical fiber with an extremely small diameter that limits beams to a few angles, resulting in an almost horizontal beam. |
|
|
Term
|
Definition
| An IPv6 address for a site having several networks, but not connected to the Internet. |
|
|
Term
|
Definition
| A protocol for key exchange designed by Hugo Krawcyzk. It is one of the three protocols that form the basis of IKE. |
|
|
Term
|
Definition
| Propagation of radio waves into the ionosphere and then back to earth. |
|
|
Term
|
Definition
| A shorthand method to indicate the number of 1s in the mask. |
|
|
Term
|
Definition
| In a piconet, a station under control of a master. |
|
|
Term
|
Definition
| A protocol that allows several data units to be in transition before receiving an acknowledgment. |
|
|
Term
|
Definition
| An error-control protocol using sliding window concept. |
|
|
Term
|
Definition
| The modified ALOHA access method in which time is divided into slots and each station is forced to start sending data only at the beginning of the slot. |
|
|
Term
|
Definition
| A RIP shortcoming apparent when a change somewhere in the internet propagates very slowly through the rest of the internet. |
|
|
Term
|
Definition
| A congestion-control method in which the congestion window size increases exponentially at first. |
|
|
Term
|
Definition
| An end point for a process; two sockets are needed for communication. |
|
|
Term
|
Definition
| A structure holding an IP address and a port number. |
|
|
Term
|
Definition
| An API based on UNIX that defines a set of system calls (procedures) that are an extension of system calls used in UNIX to access files. |
|
|
Term
|
Definition
| A RIP response sent only in answer to a request. |
|
|
Term
|
Definition
| The address of the sender of the message. |
|
|
Term
|
Definition
| A method, used in ICMP for flow control, in which the source is advised to slow down or stop the sending of datagrams because of congestion. |
|
|
Term
|
Definition
| An ICMP message sent to slow down or stop the sending of datagrams. |
|
|
Term
|
Definition
| Explicitly defining the route of a packet by the sender of the packet. |
|
|
Term
|
Definition
| A source or destination station that performs some of the duties of a transparent bridge as a method to prevent loops. |
|
|
Term
|
Definition
| A tree used for multicasting by multicasting protocols in which a single tree is made for each combination of source and group. |
|
|
Term
| source-to-destination delivery |
|
Definition
| The transmission of a message from the original sender to the intended recipient. |
|
|
Term
|
Definition
| A type of propagation that can penetrate the ionosphere. |
|
|
Term
|
Definition
| Switching in which the paths are separated from each other spatially. |
|
|
Term
|
Definition
| A tree with the source as the root and group members as leaves; a tree that connects all of the nodes. |
|
|
Term
|
Definition
| An algorithm that prevents looping when two LANs are connected by more than one bridge. |
|
|
Term
|
Definition
| Compressing an image by removing redundancies. |
|
|
Term
|
Definition
| An IGMP query message sent by a router to ensure that no host or router is interested in continuing membership in a group. |
|
|
Term
| specific host on this network |
|
Definition
| A special address in which the netid is all 0s and the hostid is explicit. |
|
|
Term
|
Definition
| The range of frequencies of a signal. |
|
|
Term
|
Definition
| A method to improve RIP stability in which the router selectively chooses the interface from which updating information is sent. |
|
|
Term
|
Definition
| A wireless transmission technique that requires a bandwidth several times the original bandwidth. |
|
|
Term
|
Definition
| The conventional Ethernet operating at 10 mbps. |
|
|
Term
|
Definition
| A backbone in which the logical topology is a star. |
|
|
Term
|
Definition
| A topology in which all stations are attached to a central device (hub). |
|
|
Term
|
Definition
| In asynchronous transmission, a bit to indicate the beginning of transmission. |
|
|
Term
| start frame delimiter (SFD) |
|
Definition
| A 1-byte field in the IEEE 802.3 frame that signals the beginning of the readable (nonpreamble) bit stream. |
|
|
Term
|
Definition
| A diagram to illustrate the states of a finite state machine. |
|
|
Term
|
Definition
| On the World Wide Web, a fixed-content document that is created and stored in a server. |
|
|
Term
|
Definition
| A technique in which a list of logical and physical address correspondences is used for address resolution. |
|
|
Term
|
Definition
| A type of routing in which the routing table remains unchanged. |
|
|
Term
|
Definition
| A host that remains attached to one network. |
|
|
Term
|
Definition
| A TDM technique in which slots are dynamically allocated to improve efficiency. |
|
|
Term
|
Definition
| In the HTTP response message a line that consists of the HTTP version, a space, a status code, a space, a status phrase. |
|
|
Term
|
Definition
| In asynchronous transmission, one or more bits to indicate the end of transmission. |
|
|
Term
|
Definition
| An error-control protocol using stop-and-wait flow control. |
|
|
Term
|
Definition
| A protocol in which the sender sends on frame, stops until it receives confirmation from the receiver, and then sends the next frame. |
|
|
Term
|
Definition
| A switch that stores the frame in an input buffer until the whole packet has arrived. |
|
|
Term
|
Definition
| A type of fiber-optic cable connector using a bayonet locking system. |
|
|
Term
| Stream Control Transmission Protocol (SCTP) |
|
Definition
| The transport layer protocol designed for Internet telephony and related applications. |
|
|
Term
|
Definition
| A structure designed to be used with a connection-oriented protocol such as TCP. |
|
|
Term
| streaming live audio/video |
|
Definition
| Broadcast data from the Internet that a user can listen to or watch. |
|
|
Term
| streaming stored audio/video |
|
Definition
| Data downloaded as files from the Internet that a user can listen to or watch. |
|
|
Term
|
Definition
| Creating two message with the same digest. |
|
|
Term
| Structure of Management Information (SMI) |
|
Definition
| In SNMP, a component used in network management. |
|
|
Term
| STS multiplexer/demultiplexer |
|
Definition
| A SONET device that multiplexes and demultiplexes signals. |
|
|
Term
|
Definition
| A network that is connected to only one router. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| The network address of a subnet. |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| subscriber channel connector |
|
Definition
| A fiber-optic cable connector using a push/pull locking mechanism. |
|
|
Term
|
Definition
| A bit-level encryption method in which n bits substitute for another n bits as defined by P-boxes, encoders, and decoders. |
|
|
Term
|
Definition
| For a network, the varying part (similar to the hostid) of the address. In DNS, a string used by an organization to define its host or resources. |
|
|
Term
| summary link to AS boundary router LSA |
|
Definition
| An LSA packet that lets a router inside an area know the route to an autonomous boundary router. |
|
|
Term
| summary link to network LSA |
|
Definition
| An LSA packet that finds the cost of reaching networks outside of the area. |
|
|
Term
|
Definition
| A signal composed of five multiplexed groups. |
|
|
Term
|
Definition
| A network formed from two or more smaller networks. |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| A device connecting multiple communication lines together. |
|
|
Term
|
Definition
| An Ethernet in which a switch, replacing the hub, can direct a transmission to its destination. |
|
|
Term
| switched virtual circuit (SVC) |
|
Definition
| A virtual circuit transmission method in which a virtual circuit is created and in existence only for the duration of the exchange. |
|
|
Term
|
Definition
| A temporary 56-Kbps digital connection between two users. |
|
|
Term
|
Definition
| The place where telephone switches are located. |
|
|
Term
| symmetric digital subscriber line (SDSL) |
|
Definition
| A DSL-based technology similar to HDSL, but using only one single twisted-pair cable. |
|
|
Term
|
Definition
| The key used for both encryption and decryption. |
|
|
Term
| symmetric-key cryptography |
|
Definition
| A cipher in which the same key is used for encryption and decryption. |
|
|
Term
|
Definition
| Reference points introduced into the data by the session layer for the purpose of flow and error control. |
|
|
Term
| synchronous connection oriented (SCO) link |
|
Definition
| In a Bluetooth network, a physical link created between a master and a slave that reserves specific slots at regular intervals. |
|
|
Term
| Synchronous Digital Hierarchy (SDH) |
|
Definition
| The ITU-T equivalent of SONET. |
|
|
Term
| Synchronous Optical Network (SONET) |
|
Definition
| A standard developed by ANSI for fiber optic technology that can transmit high-speed data. It can be used to deliver text, audio, and video. |
|
|
Term
| synchronous payload envelope (SPE) |
|
Definition
| The part of the SONET frame containing user data and transmission overhead. |
|
|
Term
|
Definition
| A TDM technique in which each input has an allotment in the output even when it is not sending data. |
|
|
Term
|
Definition
| A transmission method that requires a constant timing relationship between the sender and the receiver. |
|
|
Term
| synchronous transport module (STM) |
|
Definition
| A signal in the SDH hierarchy. |
|
|
Term
| synchronous transport signal (STS) |
|
Definition
| A signal in the SONET hierarchy. |
|
|
Term
|
Definition
| A sequence of bit generated by applying the error checking function to a codeword. |
|
|
Term
|
Definition
| The structure or format of data, meaning the order in which they are presented. |
|
|
Term
|
Definition
| A hierarchy of digital lines designed to carry speech and other signals in digital forms. The hierarchy defined T-1, T-2, T-3, and T-4 lines. |
|
|
Term
|
Definition
| A formatting instruction embedded in an HTML document. |
|
|
Term
|
Definition
| The toll office in a telephone network. |
|
|
Term
|
Definition
| The timers used by TCP to handle retransmission, zero window-size advertisements, long idle connections, and connection termination. |
|
|
Term
|
Definition
| A group of hierarchical protocols used in an internet. |
|
|
Term
|
Definition
| A time-division switch in which the input and output lines are connected to a high-speed bus through microswitches. |
|
|
Term
|
Definition
| In virtual circuit switching, the phase in which the source and destination inform the switch to erase their entry. |
|
|
Term
|
Definition
| Exchange of information over distance using electronic equipment. |
|
|
Term
|
Definition
| Audio and visual communication between remote users. |
|
|
Term
|
Definition
| A system of satellites that provides fiber-optic communication (broadband channels, low error rate, and low delay) |
|
|
Term
| telephone user port (UTP) |
|
Definition
| A protocol at the upper layer of SS7 that is responsible for setting up voice calls. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| An MPEG compression method in which redundant frames are removed. |
|
|
Term
|
Definition
| The new implementation of Ethernet operating at 10 Gbps. |
|
|
Term
| Terminal Network (TELNET) |
|
Definition
| A general purpose client-server program that allows remote login. |
|
|
Term
|
Definition
| A PPP state in which several packets are exchanged between the two ends for house cleaning and closing the link. |
|
|
Term
|
Definition
| An electronic device that prevents signal reflections at the end of a cable. |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| A switch at the network layer; a router. |
|
|
Term
|
Definition
| A sequence of events for connection establishment or termination consisting of the request, then the acknowledgment of the request, and then confirmation of the acknowledgment. |
|
|
Term
|
Definition
| A sequence of events for connection establishment or termination consisting of the request, then the acknowledgment of the request, and then confirmation of the acknowledgment. |
|
|
Term
|
Definition
| The number of bits that can pass through a point in one second. |
|
|
Term
|
Definition
| An encrypted message containing a session key. |
|
|
Term
| ticket-granting server (TGS) |
|
Definition
| A Kerberos server that issues tickets. |
|
|
Term
| time division duplexing TDMA (TDD-TDMA) |
|
Definition
| In a Bluetooth network, a kind of half-duplex communication in which the slave and receiver send and receive data, but not at the same time (half-duplex). |
|
|
Term
| time division multiple access (TDMA) |
|
Definition
| A multiple access method in which the bandwidth is just one time-shared channel. |
|
|
Term
|
Definition
| The lifetime of a packet. |
|
|
Term
| time-division multiplexing (TDM) |
|
Definition
| The technique of combining signals coming from low-speed channels to share time on a high-speed path. |
|
|
Term
|
Definition
| A circuit-switching technique in which time-division multiplexing is used to achieve switching. |
|
|
Term
|
Definition
| A graphical representation of a signal's amplitude versus time. |
|
|
Term
|
Definition
| An ICMP message sent to inform a source that (1) its datagram has a time-to-live value of zero, or (2) the fragments of a message have not been received within a set time limit. |
|
|
Term
| time-slot interchange (TSI) |
|
Definition
| A time-division switch consisting of RAM and a control unit. |
|
|
Term
|
Definition
| An IP header option used to record the time of datagram processing by a router. Also, a method to handle jitter in interactive real-time audio/video. |
|
|
Term
| timestamp-request and reply message |
|
Definition
| An ICMP message sent to determine the round-trip time or to synchronize clocks. |
|
|
Term
|
Definition
| A TCP timer used in connection termination that allows late segments to arrive. |
|
|
Term
|
Definition
| A hierarchy of digital lines designed to carry speech and other signals in digital forms. The hierarchy defines T-1, T-2, T-3, and T-4 lines. |
|
|
Term
|
Definition
| A small packet used in token-passing access method. |
|
|
Term
|
Definition
| An algorithm that allows idle hosts to accumulate credit for the future in the form of tokens. |
|
|
Term
|
Definition
| An access method in which a token is circulated in the network. The station that captures the token can send data. |
|
|
Term
|
Definition
| A LAN using a ring topology and token-passing access method. |
|
|
Term
|
Definition
| An inter-LATA or intra-LATA telephone service charged to the caller. |
|
|
Term
|
Definition
| The structure of a network including physical arrangement of devices. |
|
|
Term
|
Definition
| A telephone dialing method in which each key is represented by two small bursts of analog signals. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A method for shaping and controlling traffic in a wide area network. |
|
|
Term
|
Definition
| A mechanism to control the amount and the rate of the traffic sent to the network to improve QoS. |
|
|
Term
|
Definition
| Control information appended to a data unit. |
|
|
Term
| transaction capablities application port (TCAP) |
|
Definition
| A protocol at the upper layer of SS7 that provides remote procedure calls that let an application program on a computer invoke a procedure on another computer. |
|
|
Term
|
Definition
| A device that both transmits and receives. |
|
|
Term
|
Definition
| In Ethernet, the cable that connects the station to the transceiver. Also called the attachment unit interface. |
|
|
Term
|
Definition
| A network with several routers attached to it. |
|
|
Term
|
Definition
| The different phases through which a PPP connection goes. |
|
|
Term
|
Definition
| Changing from one code or protocol to another. |
|
|
Term
| Transmission Control Protocol (TCP) |
|
Definition
| A transport protocol in the TCP/IP protocol suite. |
|
|
Term
| Transmission Control Protocol/Internetworking Protocol (TCP/IP) |
|
Definition
| A five-layer protocol suite that defines the exchange of transmissions across the Internet. |
|
|
Term
|
Definition
| The physical path linking two communication devices. |
|
|
Term
|
Definition
| In ATM, the physical connection between two switches. |
|
|
Term
|
Definition
| The number of bits sent per second. |
|
|
Term
|
Definition
| The ability to send any bit pattern as data without it being mistaken for control bits. |
|
|
Term
|
Definition
| Another name for a learning bridge. |
|
|
Term
|
Definition
| Data that can contain control bit patterns without being interpreted as control. |
|
|
Term
|
Definition
| The fourth layer in the Internet and OSI model; responsible for reliable end-to-end delivery and error recovery. |
|
|
Term
| Transport Layer Security (TLS) |
|
Definition
| A security protocol at the transport level designed to provide security on the WWW. |
|
|
Term
|
Definition
| A character-level encryption method in which the position of the character changes. |
|
|
Term
|
Definition
| A modulation technique that includes error correction. |
|
|
Term
|
Definition
| A two-dimensional method of finding a location given the distances from 3 different points. |
|
|
Term
|
Definition
| A unit of data consisting of three bits. |
|
|
Term
|
Definition
| A two-dimensional method of finding a location given the distances from 3 different points. |
|
|
Term
|
Definition
| An algorithm compatible with DES that uses three DES blocks and two 56-bit keys. |
|
|
Term
| Trivial File Transfer Protocol (TFTP) |
|
Definition
| An unreliable TCP/IP protocol for file transfer that does not require complex interaction between client and server. |
|
|
Term
|
Definition
| Transmission media that handle communications between offices. |
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Term
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Definition
| In multicasting, a process in which the multicast packet is encapsulated in a unicast packet and then sent through the network. In VPN, the encapsulation of an encrypted IP datagram in a second outer datagram. For IPv6, a strategy used when two computers using IPv6 want to communicate with each other when the packet must pass through a region that uses IPv4. |
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Term
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Definition
| A transmission medium consisting of two insulated conductors in a twisted configuration. |
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Term
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Definition
| An Ethernet using twisted-pair cable; 10Base-T. |
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Term
| two-dimensional parity check |
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Definition
| An error detection method in two dimensions. |
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Term
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Definition
| A bridge with many ports and a design that allows better (faster) performance. |
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Term
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Definition
| A criteria or value that specifies the handling of the datagram. |
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Term
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Definition
| An HDLC unnumbered frame carrying link management information. |
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Term
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Definition
| An HDLC configuration in which one device is primary and the others secondary. |
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Term
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Definition
| A transmission medium with no physical boundaries. |
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Term
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Definition
| An address belonging to one destination. |
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Term
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Definition
| A message sent to just one destination. |
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Term
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Definition
| The sending of a packet to just one destination. |
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Term
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Definition
| The sending of a packet to just one destination. |
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Term
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Definition
| The international character set used to define valid characters in computer science. |
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Term
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Definition
| An antenna that sends or receives signals in one direction. |
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Term
| Uniform Resource Locator (URL) |
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Definition
| A string of characters (address) that identifies a page on the World Wide Web. |
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Term
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Definition
| A digital-to-digital encoding method in which one nonzero value represents either 1 or 0; the other bit is represented by a zero value. |
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Term
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Definition
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Term
| unshielded twisted-pair (UTP) |
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Definition
| A cable with wires that are twisted together to reduce noise and crosstalk. See also twisted-pair cable and shielded twisted-pair. |
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Term
| unspecified bit rate (UBR) |
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Definition
| The data rate of an ATM service class specifying only best-effort delivery. |
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Term
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Definition
| A BGP message used by a router to withdraw destinations that have been advertised previously or to announce a route to a new destination. |
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Term
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Definition
| Transmission from an earth station to a satellite. |
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Term
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Definition
| Sending a local file or data to a remote site. |
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Term
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Definition
| In an HFC network, the 5 to 42 MHz band for data from the subscriber premises to the Internet. |
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Term
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Definition
| An SMTP component that prepares the message, creates the envelope, and puts the message in the envelope. |
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Term
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Definition
| A security measure in which the sender identity is verified before the start of a communication. |
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Term
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Definition
| The name of the packet in the UDP protocol. |
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Term
| User Datagram Protocol (UDP) |
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Definition
| A connectionless TCP/IP transport layer protocol. |
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Term
| user network interface (UNI) |
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Definition
| The interface between a user and the ATM network. |
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Term
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Definition
| The session, presentation, and application layers. |
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Term
| user-to-network interface (UNI) |
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Definition
| In ATM, the interface between an end point (user) and an ATM switch. |
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Term
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Definition
| ITU-T standards that define data transmission over telephone lines. Some common standards are V.32, V32bis, V.90, and V92. |
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Term
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Definition
| The data rate of an ATM service class for users needing a varying bit rate. |
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Term
| very high bit rate digital subscriber line (VDSL) |
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Definition
| A DSL-based technology for short distances. |
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Term
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Definition
| Recording or transmitting of a picture or a movie. |
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Term
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Definition
| In an HFC network, the band from 54 to 550 MHz for downstream video. |
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Term
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Definition
| A polyalphabetic substitution scheme that uses the position of a character in the plaintext and the character's position in the alphabet. |
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Term
| virtual channel identifier (VCI) |
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Definition
| A field in an ATM cell header that defines a channel. |
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Term
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Definition
| A logical circuit made between the sending and receiving computer. The connection is made after both computers do handshaking. After the connection, all packets follow the same route and arrive in sequence. |
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Term
| virtual circuit approach to packet switching |
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Definition
| A packet switching method in which all packets of a message or session follow the exact same route. |
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Term
| virtual circuit identifier (VCI) |
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Definition
| A field in an ATM cell header that defines a channel. |
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Term
| virtual circuit switching |
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Definition
| A switching technique used in switched WANs. |
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Term
| virtual connection identifier |
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Definition
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Term
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Definition
| An OSPF connection between two routers that is created when the physical link is broken. The link between them uses a longer path that probably goes through several routers. |
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Term
| virtual local area network (VLAN) |
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Definition
| A technology that divides a physical LAN into virtual workgroups through software methods. |
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Term
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Definition
| In ATM, a connection or set of connections between two switches. |
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Term
| virtual path identifier (VPI) |
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Definition
| A field in an ATM cell header that identifies a path. |
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Term
| virtual path identifier/virtual channel identifier (VPI/VCI) |
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Definition
| Two fields used together to route an ATM cell. |
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Term
| virtual private network (VPN) |
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Definition
| A technology that creates a network that is physically public, but virtually private. |
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Term
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Definition
| A partial payload that can be inserted into a SONET frame and combined with other partial payloads to fill out the frame. |
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Term
| Voice Over Frame Relay (VOFR) |
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Definition
| A Frame Relay option that can handle voice data. |
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Term
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Definition
| A technology in which the Internet is used as a telephone network. |
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Term
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Definition
| In CDMA, a two-dimensional table used to generate orthogonal sequences. |
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Term
| wave-division multiplexing (WDM) |
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Definition
| The combining of modulated light signals into one signal. |
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Term
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Definition
| The distance a simple signal can travel in one period. |
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Term
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Definition
| Given a digest, creating a second message with the same digest. |
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Term
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Definition
| Synonym for World Wide Web (WWW). |
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Term
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Definition
| A unit of hypertext or hypermedia available on the Web. |
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Term
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Definition
| A packet scheduling technique to improve QoS in which the packets are assigned to queues based on a given priority number. |
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Term
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Definition
| Path information that every BGP router must recognize. |
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Term
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Definition
| A port number that identifies a process on the server. |
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Term
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Definition
| A port number that identifies a process on the server. |
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Term
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Definition
| A network that uses a technology that can span a large geographical distance. |
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Term
| wide area telephone service (WATS) |
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Definition
| A telephone service in which the charges are based on the number of calls made. |
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Term
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Definition
| The size of the sliding window used in flow control. |
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Term
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Definition
| Data transmission using unguided media. |
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Term
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Definition
| A LAN which uses unguided media. |
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Term
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Definition
| A multimedia Internet service that allows users to traverse the Internet by moving from one document to another via links that connect them together. |
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Term
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Definition
| An ITU-T standard that defines the interface between a data terminal device and a packet-switching network. |
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Term
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Definition
| An ITU-T standard for public key infrastructure (PKI). |
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Term
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Definition
| In DNS, what a server is responsible for or has authority over. |
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