Term
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Definition
| One of the most popular of all the IPv6 tunneling standards, and one of only two IPv6 tunneling protocols that can go through a NAT. |
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Term
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Definition
| The dominant IPv6 tunneling protocal because it is the only IPv6 tunnel that doesn't require a tunnel broker. It is generally used to directly connect two routers because it normally requires a public IPv4 address. |
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Term
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Definition
| Fiber-optic implementation of Ethernet that runs at 10 megabits per second (Mbps) using baseband signaling. Maximum segment length is 2 km. |
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Term
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Definition
| An Ethernet LAN designed to run on UTP cabling. Runs at 10 Mbps and uses baseband signaling. Maximum length for the cabling between the NIC and the hub (or the switch, the repeater, and so forth) is 100 m. |
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Term
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Definition
| A 10 GbE standard using 1550-nm single-mode fiber. Maximum cable length up to 40 km. |
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Term
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Definition
| A 10 GbE standard using 1310-nm single-mode fiber. Maximum cable length up to 10 km. |
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Term
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Definition
| A 10 GbE standard using 850-nm multimode fiber. Maximum cable length up to 300m. |
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Term
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Definition
| A 10 GbE standard designed to run on CAT 6a UTB cabling. Maximum cable length of 100m. |
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Term
| 10 Gigabit Ethernet (10 GbE) |
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Definition
| Currently (2012) the fastest Ethernet designation available, with a number of fiber-optic and copper standards. |
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Term
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Definition
| An Ethernet LAN designed to run on fiber-optic cabling. Runs at 100 Mbps and uses baseband signaling. Maximum cable length is 400 m for half-duplex and 2 km for full-duplex. |
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Term
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Definition
| An Ethernet LAN designed to run on UTP cabling. Runs at 100 Mbps, uses baseband signaling, and uses two pairs of wires on CAT 5 or better cabling. |
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Term
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Definition
| An Ethernet LAN designed to run on UTP cabling. Runs at 100 Mbps and uses four-pair CAT 3 or better cabling. Made obsolete by 100BaseT. |
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Term
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Definition
| The technically accurate but little-used name for 100BaseT. |
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Term
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Definition
| The most common connection used on the back of an RJ-45 jack and patch panels. |
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Term
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Definition
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Term
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Definition
| The IEEE committee responsible for all Ethernet standards. |
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Term
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Definition
| A port-authentication network access control mechanism for networks. |
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Term
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Definition
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Term
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Definition
| The IEEE standard for 1000BaseT. |
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Term
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Definition
| The umbrella IEEE standard for all versions of Gigabit Ethernet other than 1000BaseT. |
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Term
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Definition
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Term
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Definition
| A wireless standard that operates in the frequency range of 5 GHz and offers throughput of up to 54 Mbps. |
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Term
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Definition
| The first popular wireless standard, which operates in the frequency range of 2.4 GHz and offers throughput of up to 11 Mbps. |
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Term
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Definition
| Currently (2012) the wireless standard with the widest use, 802.11g operates on the 2.4 GHz band with a maximum throughput of 54 Mbps. |
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Term
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Definition
| A wireless standard that added security features. |
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Term
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Definition
| An updated 802.11 standard that increases transfer speeds and adds support for multiple in/multiple out (MIMO) by using multiple antennas. 802.11n can operate on either the 2.4- or 5-GHz frequency band and has a maximum throughput of 400 Mbps. |
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Term
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Definition
| A wireless standard (also known as WiMax) with a range of up to 30 miles. |
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Term
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Definition
| A Gigabit Ethernet standard using unique copper cabling, with a 25-m maximum cable distance. |
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Term
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Definition
| A Gigabit Ethernet standard using single-mode fiber cablig, with a 220- to 500-m maximum cable distance. |
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Term
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Definition
| A Gigabit Ethernet standard using multimode fiber cabling, with a 5-km maximum cable distance. |
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Term
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Definition
| A Gigabit Ethernet standard using CAT 5e/6 UTP cabling, with a 100-m maximum cable distance. |
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Term
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Definition
| An umbrella Gigabit Ethernet standard. Also known as 802.3z. Comprises all Gigabit standards with the exception of 1000BaseT, which is under the 802.3ab standard. |
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Term
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Definition
| A list of the IP addresses and names of all the systems on a DNS server domain. |
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Term
| AAA (Authentication, Authorization, and Accounting) |
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Definition
| See Authentication, Authorization, and Accounting (AAA). |
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Term
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Definition
| A document that defines what a person may and may not do on an organization's computers and networks. |
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Term
| Access Control List (ACL) |
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Definition
| A clearly defined list of permissions that specifies what actions an authenticated user may perform on a shared resource. |
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Term
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Definition
| A form of directory service used in networks with Windows servers. Creates an organization of related computers that share one or more Windows domains. |
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Term
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Definition
| An LED on a NIC, hub, or switch that blinks rapidly to show data transfers over the network. |
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Term
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Definition
| A wireless networking mode where each node is in direct contact with every other node in a decentralized free-for-all. Ad hoc mode is similar to the mesh topology. |
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Term
| Address Resolution Protocol (ARP) |
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Definition
| A protocol in the TCP/IP suite used with the command-line utility of the same name to determine the MAC address that corresponds to a particular IP address. |
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Term
| ADSL (Asymmetric Digital Subscriber Line) |
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Definition
| See Asymmetric Digital Subscriber Line (ADSL). |
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Term
| Advanced Encryption Standard (AES) |
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Definition
| A block cipher created in the late 1990s that uses a 128-bit block size and a 128-, 192-, or 256-bit key size. Practically uncrackable. |
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Term
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Definition
| A program that monitors the types of Web sites you frequent and uses that information to generate targeted advertisements, usually pop-up windows. |
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Term
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Definition
| A router hierarachy in which every router underneath a higher router always uses a subnet of that router's existing routes. |
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Term
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Definition
| A set of rules for solving a problem in a given number of steps. |
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Term
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Definition
| A method of addressing groups of computers as though they were a single computer. Anycasting starts by giving a number of computers (or clusters of computers) the same IP address. Advanced routers then send incoming packets to the closest of the computers. |
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Term
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Definition
| An open-source HTTP server program that runs on a wide variety of operating systems. |
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Term
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Definition
| See Open System Interconnection (OSI) Seven-Layer Model. |
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Term
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Definition
| Tracks application events, such as when an application opens or closes. Different types of application logs record different events. |
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Term
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Definition
| An attribute of a file that shows whether the file has been backed up since the last change. Each time a file is opened, changed, or saved, the archive bit is turned on. Some types of backups turn off this archive bit to indicate that a good backup of the file exists on tape. |
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Term
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Definition
| Address assigned to routers in an OSPF network to prevent flooding beyond the routers in that particular network. See also Open Shortest Path First (OSPF). |
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Term
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Definition
| A command used to discover hosts on a network, similar to ing, but that relies on ARP rather than ICMP. The arping command won't cross any routers, so it will only work within a broadcast domain. See also Address Resolution Protocol (ARP) and ping. |
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Term
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Definition
| Managing each aspect of a network, from documentation to performance to hardware. |
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Term
| Asymmetric Digital Subscriber Line (ADSL) |
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Definition
| A fully digital, dedicated connection to the telephone system that provides download speeds of up to 9 Mbps and upload speeds of up to 1 Mbps. |
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Term
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Definition
| An enccryption method in which the key used to encrypt a message and the key used to decrypt it are different, or asymmetrical. |
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Term
| Asynchronous Transfer Mode (ATM) |
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Definition
| A network technology that runs at speeds between 25 and 622 Mbps using fiber-optic cabling or CAT 5 or better UTP. |
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Term
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Definition
| The degradation of signal over distance for a networking cable. |
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Term
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Definition
| A process that proves good data traffic truly came from where it say it originated by verifying the sending and recieving users and computers. |
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Term
| Authentication, Authorization, and Accounting (AAA) |
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Definition
| A security philosophy wherein a computer trying to connect to a network must first present some form of credential in order to be authenticated and then must have limitable permissions within the network. The authenticating server should also record session information about the client. |
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Term
| Authentication Server (AS) |
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Definition
| In Kerberos, a system that hands out Ticket-Granting Tickets to clients after comparing the client hash to its own. See also Ticket-Granting Ticket (TGT). |
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Term
| Authoritative DNS Servers |
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Definition
| DNS servers that hold the IP addresses and names of systems for a particular domain or domains in special storage areas called foward lookup zones. |
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Term
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Definition
| A step in the AAA philosophy during which a client's permissions are decided upon. See also Authentication, Authorization, and Accounting (AAA). |
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Term
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Definition
| One or more networks that are governed by a single protocol within that AS, which provides routing for the Internet backbone. |
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Term
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Definition
| To save important data in a secondary location as a safety precaution against the loss of the primary data. |
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Term
| Backup Designated Router (BDR) |
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Definition
| A second router set to take over if the designated router fails. See also Designated Router (DR). |
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Term
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Definition
| An onsite generator that provides electricity if the power utility fails. |
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Term
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Definition
| A piece of the spectrum occupied by some form of signal, whether it is television, voice, fax data, and so forth. Signals require a certain size and location of bandwidth to be transmitted. The higher the bandwidth, the faster the signal transmission, thus allowing for a more complex signal such as audio or video. Because bandwidth is a limited space, when one user is occupying it, others must wait their turn. Bandwidth is also the capacity of a network to transmit a given amount of data during a given period. |
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Term
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Definition
| Digital signaling that only one signal (a single signal) on the cable at a time. The signals must be in one of three states: one, zero, or idle. |
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Term
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Definition
| Static image of a system's (or network's) performance when all elements are known to be working properly. |
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Term
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Definition
| A simple form of NAT that translates a computer's private or internal IP address to a global IP address on a one-to-one basis. |
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Term
| Basic Rate Interface (BRI) |
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Definition
| The basic ISDN configuration, which consists of two B channels (which can carry voice or data at a rate of 64 Kbps) and one D channel (which carries setup and configuration information, as well as data, at 16 Kbps). |
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Term
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Definition
| In wireless networking, a single access point servicing a given area. |
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Term
| Basic Service Set Identifier (BSSID) |
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Definition
| Naming scheme in wireless networks. |
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Term
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Definition
| One analog cycle on a telephone line. |
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Term
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Definition
| The number of bauds per second. In the early days of telephone transmission, the baud rate was often analogous to bits per second. Due to advanced modulation of baud cycles as well as data compression, this is no longer true. |
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Term
| Bearer Channel (B Channel) |
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Definition
| A type of ISDN channel that carries data and voice information using standard DS0 channels at 64 Kbps. |
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Term
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Definition
| Devices that scan fingerprints, retinas, or even the sound of the user's voice to provide a foolproof replacement for both passwords and smart devices. |
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Term
| Bit Error Rate Test (BERT) |
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Definition
| An end-to-end test that verifies a T-carrier connection. |
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Term
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Definition
| An encrpytion algorithm in which data is encrypted in "chunks" of a certain length at a time. Popular in wired networks. |
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Term
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Definition
| A connector used for 10Base2 coaxial cable. All BNC connectors have to be locked into place by turning the locking ring 90 degrees. |
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Term
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Definition
| Two or more NICs in a system working together to act as a single NIC to increase performance. |
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Term
| Bootstrap Protocol (BOOTP) |
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Definition
| A component of TCP/IP that allows computers to discover and recieve an IP address from a DHCP server prior to booting the OS. Other items that may be discovered during the BOOTP process are the IP address of the default gateway for the subnet and the IP addresses of any name servers. |
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Term
| Border Gateway Protocol (BGP-4) |
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Definition
| An exterior gateway routing protocol that enables groups of routers to share routing information so that efficient, loop-free routes can be established. |
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Term
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Definition
| A group of computers under the control of one operator, used for malicious purposes. |
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Term
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Definition
| A mesurement of how fast data is moved across a transmission medium. A Gigabit Ethernet connection moves 1,000,000,000,000 bps. |
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Term
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Definition
| A device that connects two networks and passes traffic between them based only on the node address, so that traffic between nodes on one network does not appear on the other network. For example, an Ethernet bridge only looks at the MAC address. Bridges filter and forward frames based on MAC addresses and operate at Layer 2 (Data Link layer) of the OSI seven-layer model. |
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Term
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Definition
| A negative situation in which bridging devices (usually switches) are installed in a loop configuration, causing frames to loop continuously. Switches using Spanning Tree Protocol (STP) prevent bridge loops by automatcially turning off loop ports. |
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Term
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Definition
| An early type of DSL connection that made the DSL line function the same as if you snapped an Ethernet cable into your NIC. |
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Term
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Definition
| Analog signaling that sends multiple signals over the cable at the same time. The best example of broadband signaling is cable television. The zero, one, and idle states exist on multiple channels on the same cable. See also Baseband. |
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Term
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Definition
| A frame or packet addressed to all machines, almost always limited to a broadcast domain. |
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Term
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Definition
| The address a NIC attaches to a frame when it wants every other NIC on the network to read it. In TCP/IP, the general broadcast address is 255.255.255.255. In Ethernet, the broadcast MAC address is FF-FF-FF-FF-FF-FF. |
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Term
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Definition
| A network of computers that will hear each other's broadcasts. The older term collision domain is the same, but rarely used today. |
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Term
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Definition
| The result of one or more devices sending a nonstop flurry of broadcast frames on the network. |
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Term
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Definition
| A software program specifically designed to retrieve, interpret, and display web pages. |
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Term
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Definition
| Location where all cables from the outside world (telephone lines, cables from other buildings, and so on) come into a building. |
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Term
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Definition
| A network topology that uses a single bus cable that connects all of the computers in line. Bus topology networks must be terminated to prevent signal reflection. |
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Term
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Definition
| Device that can tap into a 66- or 110-punchdown block to see if a particular line is working. |
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Term
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Definition
| Eight contiguous bits, the fundamental data unit of personal computers. Storing the equivalent of one character, the byte is also the basic unit of measurement for computer storage. Bytes are counted in powers of two. |
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Term
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Definition
| Short for "cabinet files." These files are compressed and most commonly used during Microsoft operating system installation to store many smaller files, such as device drivers. |
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Term
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Definition
| A very powerful cable testing device used by professional installers to test the electrical characteristics of a cable and then generate a certification report, proving that the cable runs pass TIA/EIA standards. |
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Term
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Definition
| Location where the cable comes out of the wall at the workstation location. |
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Term
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Definition
| A bridge device that interconnects the cable company's DOCSIS service to the user's Ethernet network. In most locations, the cable modem is the demarc. |
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