Term
|
Definition
-Relatively slow speed
-Two insulated wires can be shielded (STP) or unshielded (UTP)
-UTP is a four-pair medium comes in several categories
-UTP can be easily tapped by eavesdroppers than the other cable types.
-Category based on how tightly wound the wires are, tighter the wind the higher the rating and resistance to interference. |
|
|
Term
|
Definition
| Used for telephone lines not good for data. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Used for 10BaseT networks up to 10 MBps |
|
|
Term
|
Definition
| Used in Token Ring Networks up to 16 MBps |
|
|
Term
|
Definition
| Current UTP standard for new installations up to 100 MBps |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
-Hollow outer conductor surrounds inner wire conductor. Currently two types in LANs
-50-ohm Cable for digital signaling
-75-ohm Cable for analog signaling and high speed digital signaling
-Coax is more expensive but is more resistant to Electromagnetic Interference (EMI).
-Used rarely except in Broadband communications |
|
|
Term
|
Definition
|
|
Term
|
Definition
| RG8 or RG11 coaxial cable |
|
|
Term
|
Definition
| Coaxial cable that carries a single channel |
|
|
Term
|
Definition
| Coaxial cable carries several channels such as data, voice, audio, and video |
|
|
Term
|
Definition
-Conducts modulated light transmission
-Light waves are faster and travel greater distances
-Difficult to tap
-Resistant to EMI
-Usually connects backbones in larger networks
-Can be used to connect workstations to the network.
-Expensive to install and to terminate. |
|
|
Term
| Carrier Sense Multiple Access (CSMA) |
|
Definition
-Foundation of Ethernet Protocol.
-Workstation continuously monitors the line waiting until it thinks it is free.
-If the workstation doesn’t receive an acknowledgement from the destination to which it sent the packet, it assumes a collision has occurred and it resends the packet. |
|
|
Term
|
Definition
| Unless receives acknowledgement it will resend. |
|
|
Term
| Nonpersistent Carrier Sense |
|
Definition
| Waits random amount of time and resends. |
|
|
Term
| CSMA/CA - Carrier Sense Multiple Access Collision Avoidance |
|
Definition
| Workstations connected to two coax cables, one to send and one to receive data. |
|
|
Term
| CSMA/CD - Carrier Sense Multiple Access Collision Detection – Ethernet |
|
Definition
| If the host detects another signal while transmitting it will send a jam signal causing all nodes to stop sending data. Nodes wait to resend. Designed to avoid collisions. |
|
|
Term
|
Definition
| A primary workstation polls another at a predetermined time to determine if it has data to transmit. Primary must give permission to others to transmit. |
|
|
Term
|
Definition
-Token Ring and FDDI and ARCnet
-Cannot transmit without the token
-Each station can hold token for maximum predetermined amount of time |
|
|
Term
|
Definition
| From single source to single destination |
|
|
Term
|
Definition
| Source copied and sent to multiple destinations |
|
|
Term
|
Definition
| Source copied and sent to all nodes on the network |
|
|
Term
|
Definition
-Unicast
-Multicast
-Broadcast |
|
|
Term
|
Definition
|
|
Term
|
Definition
| All nodes connected to every other node |
|
|
Term
|
Definition
| Branches can have multiple nodes |
|
|
Term
|
Definition
-Nodes connected to a central LAN or a junction box called a hub or a concentrator at the center of the network.
-Ads: reliability
-Ring and Bus often use Star as physical connection. |
|
|
Term
|
Definition
-Unidirectional transmission links form closed loop.
-Token Ring and FDDI.
-Similar to the Star topology, however there’s a device called a Multistation Access Unit (MAU).
-MAU works the same as a hub, but with Token Ring networks instead of Ethernet networks.
-These networks were originally designed to serve large, bandwidth-consuming applications. |
|
|
Term
|
Definition
-All transmissions travel full length of the cable and received by all other stations.
-Single point of failure in the cable.
-If one of the links between any of the computers is broken, the network is down.
-Primarily Ethernet.
-These networks were originally designed to work with more sporadic traffic. |
|
|
Term
|
Definition
-Based the 802.3 standard.
-Uses CSMA/CD – Designed for sporadic traffic
-Defines a bus topology with three different cabling standards
1)Thinnet – 10Base2 – coax with segments up to 185 meters.
2)Thicknet – 10BaseS – coax with segments up to 500 meters.
3)UTP – Unshielded Twisted Pair – all devices connected to a hub or switch 10BaseT 10 Mbps, 100BaseT 100 Mbps and 1000BaseT 1 GBps |
|
|
Term
|
Definition
-Based on the 802.5 standard.
-Early LAN technologies
-Uses token passing in a Star topology on coax cable. |
|
|
Term
|
Definition
-Second to Ethernet
-All end stations connected to a Multistation Access Unit (MSAU)
-One station is designated as the Active Monitor
-If a transmitting station fails, the Active monitor will remove the token and generate a new one. |
|
|
Term
| Fiber Distributed Data Interface – FDDI |
|
Definition
-Dual token ring LAN at 100 MBps on Fiber
-Dual counter rotating rings only one active at a time
-Operates over long distances with minimal interference
-Predictable delays, deterministic
-Permits several tokens to be present at a time
-Expensive and requires expertise
-Copper Distributed Data Interface (CDDI) – can be used with UTP cable but subject to interference and length issues associated with Copper. |
|
|
Term
|
Definition
-Amplify signal, no added intelligence, no filtering
-Works at the Physical Layer (1) |
|
|
Term
|
Definition
Used to connect multiple LAN devices, no added intelligence
– Works at the Physical Layer (1) |
|
|
Term
|
Definition
-Amplify signal, add some intelligence.
-Forwards the data to all other network segments if the Media Access Control (MAC) or hardware address of the destination computer is not on the local network segment.
-Automatically forwards all broadcast traffic.
-Does not use IP address because IP is contained in the Network Layer (3)
-Works at Data Link Layer (2) |
|
|
Term
|
Definition
-Will only send data to the port where the destination MAC address is, not to all ports.
-Primarily operate at the Data Link Layer (2), although extremely fast layer 3 devices combining switching and routing are being used. |
|
|
Term
|
Definition
| -Opens packet and looks at either the MAC or IP address only forwards to the network that it is destined. -Operates at Network Layer (3) |
|
|
Term
|
Definition
| Primarily software, can be multi-protocol, can examine entire packet. Can operate at Layer 5 or 6. |
|
|
Term
|
Definition
| Remote access multi layer switch connected to host router, filters based on MAC address or Network Layer protocol, not capable of firewalling. |
|
|
Term
|
Definition
| Indefinitely and continuously reserve for transmissions |
|
|
Term
|
Definition
| Type of dedicated line leased from carrier. |
|
|
Term
| Types of speeds of Leased lines |
|
Definition
-Digital Signal Level 0 – DS-0 – single channel at 64KBps on a T1
-Digital Signal Level 1 – DS-1 – 1.544 MBps in US on a T1 and 2.108 MBps in Europe on a E1
-Digital Signal Level 3 – DS-3 – 44.736 MBps on a T3
-T1 – Transmits DS-1 data at 1.544 MBps on telephone switching network
-T3 – Transmits DS-3 data at 44.736 MBps on telephone switching network
-E1 – predominately used in Europe carries data at 2.108 MBps
-E3 - predominately used in Europe carries data at 34.368 MBps |
|
|
Term
| SLIP - Serial Line Internet Protocol |
|
Definition
| Developed in 1984 to support TCP/IP over low speed serial interfaces. Using Windows NT RAS, NT computers can use TCP/IP and SLIP to communicate to remote hosts. |
|
|
Term
| PPP - Point-to Point protocol |
|
Definition
| Over dial up and dedicated links, includes login, password, and error correction. Operates at the Data Link Layer (2) and uses CHAP and PAP. |
|
|
Term
| ISDN - Integrated Services Digital Network |
|
Definition
| Integration of digital telephony and data transport. Digitization of the telephone network, allowing voice, data, etc. Overtaken by DSL |
|
|
Term
| xDSL - Digital Subscriber Line |
|
Definition
| Uses existing twisted pair telephone lines. |
|
|
Term
| ADSL – Asymmetric Digital Subscriber Line |
|
Definition
| Provides bandwidth downstream from 1.5 to 9 MBps with upstream 16 to 640 KBps. ADSL works at 18,000 feet lengths, theoretical and 14,400 practical over single copper twisted pair. |
|
|
Term
| SDSL - Single-line (Symmetric) Digital Subscriber Line |
|
Definition
| Provides from 144 KBps up to 1.544 MBps both down and up, depending on distance, over single copper twisted pair, works at 10,000 feet lengths. |
|
|
Term
| HDSL – High-Rate Digital Subscriber Line |
|
Definition
| Provides 1.544 MBps both down and up over two copper twisted pair. Provides T1 speeds. Can do 2.048 MBps on three copper twisted pair. |
|
|
Term
| VDSL – Very-high Rate Digital Subscriber Line |
|
Definition
| Provides 13-52 MBps down and 1.5 MB to 2.3 MBps upstream over single copper twisted pair operating range 1,000 – 4,500 feet |
|
|
Term
|
Definition
-Defined as a switching system in which a physical circuit path must exist for the duration of the transmission
-Physical permanent connections from one point to another
-Older technology than Packet Switching
-Phone companies use this a lot |
|
|
Term
|
Definition
-Create virtual circuits used as needed and reduce cost.
-Defined as a switching system where nodes share bandwidth by sending small packets.
-Each packet sent to the next destination by the router.
-Packets reassembled based on original sequence |
|
|
Term
|
Definition
| Message sent from node to node and stored at each node until forwarding path is available |
|
|
Term
| Packet Switching Technologies |
|
Definition
-X.25
-Link Access Procedure Balance (LABP)
-Frame Relay
-Switched Multimegabit Data Service (SMDS)
-Asynchronous Transfer Mode (ATM)
-Voice over IP (VoIP) |
|
|
Term
|
Definition
-First packet switching network
-Supports Switched Virtual Circuits (SVCs) and Permanent Virtual Circuits (PVCs)
-Designed to operate effectively regardless of the type of systems connected to
-Currently much more predominant overseas than in the US |
|
|
Term
| Link Access Procedure Balance (LAPB) |
|
Definition
-Designed for use with X.25
-Defines frame types
-Can retransmit, exchange and detect out of sequence frames or missing frames. |
|
|
Term
|
Definition
-High performance WAN protocol
-Operates at Physical and Data Link Layers (1 and 2)
-Originally designed for ISDN
-Replaces X.25 and LAPB
-Simple and fast, no error correcting
-Supports Switched Virtual Circuits (SVCs) and Permanent Virtual Circuits (PVCs)
-Not available everywhere |
|
|
Term
| Switched Multimegabit Data Service (SMDS) |
|
Definition
-High Speed over public switched networks
-Connectionless bandwidth on demand |
|
|
Term
| Asynchronous Transfer Mode (ATM) |
|
Definition
-High bandwidth, low delay
-Uses switching and multiplexing
-Uses 53 byte fixed size cells instead of frames
-Can allocate bandwidth on demand
-Taking place of FDDI in Campus Backbone |
|
|
Term
|
Definition
-Combines media types (voice, video, data, audio) into one IP packet
-Provides benefits in cost, performance and interoperability
-Very new but far reaching potential |
|
|
Term
| Synchronous Data Link Control (SDLC) |
|
Definition
-Uses polling access method for mainframes
-Based on dedicated leased line
-Evolved into HDLC and LAPB
-Operates at Data Link Layer (2) |
|
|
Term
| High-Level Data Link Control (HDLC) |
|
Definition
-Derived from SDLC
-Specifies data encapsulation method on synchronous serial links
-Operates at Data Link Layer (2) |
|
|
Term
| High Speed Serial Interface |
|
Definition
-Defines the electrical and physical interfaces to be used by DTE/DCE
-Operates and the Physical Layer (1) |
|
|
Term
|
Definition
| MUX enables more than one signal to be sent out over one physical circuit |
|
|
Term
|
Definition
| Multi-port network devices operate at the Data Link Layer (2). Typically switch Frame Relay, X.25 and SMDS |
|
|
Term
|
Definition
| Provides dial in and dial out access connections to a network. Typically asynchronous. |
|
|
Term
|
Definition
| Interprets digital and analog signals, transmits over voice grade telephone lines. |
|
|
Term
| Channel Service Unit (CSU)/Data Service Unit (DSU) |
|
Definition
| Used to terminate the physical interface on a DTE device such as a terminal. |
|
|
Term
| Benefits of Remote Access |
|
Definition
-Reducing costs by replacing dedicated network lines
-Providing employees flexible work styles, Telecommuting
-Building efficient ties with vendors, partners, suppliers and employees. |
|
|
Term
| Asynchronous Dial up Access |
|
Definition
-How most people access Internet
-Use existing public switched phone network to access ISP |
|
|
Term
| ISDN - Integrated Services Digital Network |
|
Definition
| Carries voice, data over telephone networks, use one of two type of interface BRI or PRI |
|
|
Term
| BRI - Basiec Rate Interface |
|
Definition
| Composed of two B channels and one D Channe used in ISDN |
|
|
Term
| PRI - Primary Rate Interface |
|
Definition
| Composed of a single 64 KBps D channel plus 23(T1) or 30 (E1), used in ISDN |
|
|
Term
| xDSL - Digital Subscriber Line |
|
Definition
| Uses existing twisted pair telephone lines. |
|
|
Term
|
Definition
-High speed access from the cable company
-Users share the Coax connection
-Throughput varies depending on number of users
-Considered insecure because local segment is not filtered or firewalled (Says Who?) |
|
|
Term
|
Definition
|
|
Term
|
Definition
| 2.4 Ghz currently most popular up to 11 MBps wireless standard |
|
|
Term
|
Definition
| 2.4 Ghz but faster than 802.11b, wireless standard |
|
|
Term
|
Definition
-Wired Equivalency Protocol – up to 128-bit; uses a static key
-RC4 Stream cipher
-CRC-32 checksum |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Service Set Identifier – Network Name |
|
|
Term
| Password Authentication Protocol (PAP) |
|
Definition
-Remote security protocol. Provides Identification and Authentication.
-Uses static replayable password for authentication (now considered weak)
-Does not encrypt the User ID or Password |
|
|
Term
| Remote Identification and Authentication |
|
Definition
-Verify who is remotely communication.
-Identification - Who
-Authentication – Verify and Trust |
|
|
Term
| Challenge Handshake Protocol (CHAP) |
|
Definition
-Next evolution of PAP uses stronger authentication
-Nonreplayable Challenge/Response
-Verifies Identity of the node
-Often used to enable network-to-network communication
-Commonly used by remote access servers and xDSL, ISDN, and cable modems |
|
|
Term
|
Definition
-Checks incoming number against approved list
-Very commonly used, hard to defeat
-Hard to administer for traveling users |
|
|
Term
| Remote Access Authentication Systems |
|
Definition
-TACACS – Terminal Access Controller Access Control System (TCP)
-TACACS+ – includes the use of two factor authentication
-RADIUS – Remote Access Dial-In User Service (UDP) |
|
|
Term
|
Definition
-Caller supplies password or identifier and hangs up
-System dials back number listed for the user
-Hard to administer for traveling users |
|
|
Term
| TACACS+ Terminal Access Controller Access Control System Plus |
|
Definition
-Proprietary CISCO enhancement
-Two factor Authentication
-User can change password
-Ability to use secure tokens
-Better Audit Trails |
|
|
Term
| RADIUS – Remote Access Dial-In User Service |
|
Definition
-Offers similar benefits to TACACS+
-Often used as a stepping stone to TACACS+
-Radius Server contains dynamic password and network service access information (Network ACLS)
-Radius is a fully open protocol, can be customized for almost any security system
-Can be used with Kerberos and provides CHAP remote node authentication |
|
|
Term
|
Definition
-Independent Basic Service Set (IBSS)
-Infrastructure Basic Service Set
-Infrastructure Extended Service Set
-Service Set Identifiers (SSID) |
|
|
Term
| Independent Basic Service Set (IBSS) |
|
Definition
| Ad-hoc wireless clients talk only to other wireless clients |
|
|
Term
| Infrastruture Extended Service Set |
|
Definition
-seamless transition not guaranteed by 802.11
-Generally requires use of Moblie IP |
|
|
Term
| Infrastructure Basic Service Set |
|
Definition
| Infrastructure - clients send all packets to one Access Point (AP). AP acts as bridge into wired network |
|
|
Term
| Service Set Identifiers (SSID) |
|
Definition
| Used by vendors to uniquely identify a wireless network |
|
|
Term
| IEEE 8021.X Port-based Network Access Conttrol |
|
Definition
-IEEE adapation of IETF Extensible Authenication Protocol (EAP) specified in RFC 2284 and updated by RFC 3748
-Dynammically distributes keys for APs and client stations |
|
|
Term
| WiFi Protected Access (WPA) |
|
Definition
-WiFi Alliance implementation of IEEE draft 3.0 of 802.11i
-Enterprise mode
-Personal Mode WPA
-WPA Implements Temporal Key Integrity Protocol (TKIP) |
|
|
Term
| WiFi Protected Access 2 (WPA2) |
|
Definition
-Implements mandatory elements of IEEE 802.11i
-Impelements Counter Mode with Cipher Block Chaining Media Authentication Code Protocol (CCMP)
-Backwards compatible with WPA products using TKIP
-Officially supported by Win XP |
|
|
Term
|
Definition
-Peer-to-peer protocol created to connect multipel consumer moblie information devices transparently
-IEEE 802.15
-2.4 to 2.5 GHz with FHSS
-Transimssion distances up to 30ft |
|
|
Term
| Wireless Transport Layered Security (WTLS) Classes of Security |
|
Definition
-Class 1: Anonymous Authentication
-Class 2: Server Authenication
-Class 3: Two-way Client and Service Authentication |
|
|
