Networking Terms Ch.13

Front 1

asymmetric communication

Back 1

Communication in which data travels in the download direction at a speed different from the speed of the upload direction.

Front 2

Asymmetric Digital Subscriber Line (ADSL)

Back 2

A digital telecommunications technology that uses different speeds for downloading and uploading data.

Front 3

asynchronous

Back 3

A communication method that sends data in a stream with start and stop bits that indicate where data begins and ends.

Front 4

Basic Rate Interface (BRI)

Back 4

An ISDN version that provides two 64 Kbps B-channels. Generally used for remote connections.

Front 5

baud

Back 5

A measurement of modem speed that describes the number of state transitions occurring per second on an analog phone line.

Front 6

Binary Synchronous (bisync)

Back 6

One of the primary synchronous communication protocols.

Front 7

bridges

Back 7

Networking devices that work at the Data Link layer of the OSI model. They filter traffic according to a packet’s hardware destination address.

Front 8

bridging table

Back 8

A reference table created by a bridge to track hardware addresses and to track on which network segment each address is located.

Front 9

Broadband ISDN (B-ISDN)

Back 9

An ISDN variation that supports much higher data rates than standard ISDN and works with other technologies, such as ATM, SONET, and frame relay.

Front 10

broadcast storm

Back 10

A phenomenon that occurs when a network device malfunctions and floods the network with broadcast packets.

Front 11

Channel Service Unit/Data Service Unit (CSU/DSU)

Back 11

A device that links a computer or network to a DDS communications link.

Front 12

Committed Information Rate (CIR)

Back 12

A guaranteed minimum transmission rate offered by the service provider.

Front 13

customer premises equipment (CPE)

Back 13

The equipment at the customer site that’s usually the responsibility of the customer.

Front 14

cut-through switching

Back 14

The fastest switching method, in which the switch reads only enough of the incoming frame to determine where to forward the frame.

Front 15

data circuit-terminating equipment (DCE)

Back 15

The device that sends data to (and receives data from) the local loop, usually a CSU/DSU or modem.

Front 16

data terminal equipment (DTE)

Back 16

The device that passes data from the customer LAN to the DCE, usually a router.

Front 17

demarcation point

Back 17

The point at which the CPE ends and the provider’s equipment responsibility begins.

Front 18

Dial-Up Networking (DUN)

Back 18

The Windows program (beginning with Windows 95) that allows connectivity to servers running RAS or RRAS.

Front 19

Digital Data Service (DDS)

Back 19

A type of point-to-point synchronous communication link offering 2.4, 4.8, 9.6, or 56 Kbps transmission rates.

Front 20

digital modem

Back 20

A hardware device used to transmit digital signals across an ISDN link.

Front 21

distance-vector algorithm

Back 21

One method of determining the best route available for a packet. Distance-vector protocols count the number of routers (hops) between the source and destination. The best path has the least number of hops.

Front 22

dynamic routing

Back 22

The process by which routers dynamically learn from each other the available paths.

Front 23

fractional T1

Back 23

One or more of the 24 channels (but not all) of a T1 connection.

Front 24

fragment-free switching

Back 24

A switching method in which the switch reads in enough of the frame to guarantee that the frame is not less than the minimum frame size allowed for the network type.

Front 25

frame fragment

Back 25

A frame error that occurs because the frame is less than the allowable minimum size for the network type. A frame fragment usually occurs because of a collision or a device malfunction.

Front 26

frame relay

Back 26

A point-to-point permanent virtual circuit (PVC) technology that offers WAN communications over a fast, reliable, digital packet-switching network

Front 27

gateway

Back 27

A networking device that translates information between protocols or between completely different networks, such as from TCP/IP to SNA.

Front 28

High-level Data Link Control (HDLC)

Back 28

One of the primary synchronous communication protocols.

Front 29

hop

Back 29

A packet traveling through a router on its way to the destination network.

Front 30

Integrated Services Digital Network (ISDN)

Back 30

A WAN technology that offers increments of 64 Kbps connections,most often used by SOHO (small office/home office) users.

Front 31

last mile

Back 31

The connection between a WAN’s demarcation point and the central office (CO). See also local loop.

Front 32

line conditioning

Back 32

A feature that sustains a consistent transmission rate, improves overall quality, and reduces interference noise levels.

Front 33

link-state algorithm

Back 33

A method used by routers to determine a packet’s best path. In addition to the number of routers involved, routers using link-state algorithms take network traffic and link speed into account to determine the best path.

Front 34

local loop

Back 34

The connection between a WAN’s demarcation point and the central office (CO). See also last mile.

Front 35

metric

Back 35

A value that describes the distance to the destination network.

Front 36

modem

Back 36

A device computers use to convert digital signals to analog signals for transmission over telephone lines. The receiving computer then converts the analog signals to digital signals.

Front 37

multiplexing

Back 37

A technology that enables several communication streams to travel simultaneously over the same cable segment

Front 38

packet assembler/disassembler (PAD)

Back 38

A device that supports X.25 communications for low-speed, character-based terminals.

Front 39

permanent virtual circuits (PVCs)

Back 39

Pathways between two communication points that are established as permanent logical connections

Front 40

plain old telephone service (POTS)

Back 40

Also known as PSTN, the normal telephone communications system. See also public switched telephone network (PTSN).

Front 41

Point-to-Point Protocol (PPP)

Back 41

A remote access protocol that supports many protocols, including IP, NetBEUI, and IPX.

Front 42

Primary Rate Interface (PRI)

Back 42

An ISDN version that provides 23 64-Kbps B-channels.

Front 43

propagation delay

Back 43

Signal delay created when a number of repeaters connect in a line. To prevent this, many network architectures limit the number of repeaters on a network.

Front 44

public data networks (PDNs)

Back 44

WAN services, usually provided by private companies, for the purpose of enabling WAN technologies, such as X.25.

Front 45

public switched telephone network (PSTN)

Back 45

Another term for the public telephone system.

Front 46

pulse code modulation (PCM)

Back 46

A technique for digitizing analog signals. PCM introduces less noise into the signal than traditional modulation/demodulation techniques, thus boosting the total number of bits per second.

Front 47

routers

Back 47

Networking devices that operate at the Network layer of the OSI model. A router connects networks with different physical media and translates between different network architectures, such as token ring and Ethernet.

Front 48

routing table

Back 48

A reference table that includes network information and the next router in line for a particular path.

Front 49

Serial Line Internet Protocol (SLIP)

Back 49

The dial-up protocol originally used to connect PCs directly to the Internet.

Front 50

source-routing bridges

Back 50

A type of bridge used in IBM token ring networks that learns its bridging information from information in the frame’s structure.

Front 51

static routing

Back 51

A type of routing in which the router is configured manually with all possible routes.

Front 52

store-and-forward switching

Back 52

A switching method in which the switch reads the entire frame to check for errors before forwarding the frame.

Front 53

switched 56K

Back 53

Digital point-to-point leased communication links offered by local and long-distance telcos. Lease terms are based on per-minute use charges, not on 24-hour, seven-day dedicated circuits.

Front 54

switched virtual circuits (SVCs)

Back 54

A communication circuit that’s established when needed and then terminated when the transmission is completed.

Front 55

Symmetric Digital Subscriber Line (SDSL)

Back 55

A digital telecommunications technology that uses equivalent speeds for downloading and uploading data.

Front 56

synchronous

Back 56

A communication method in which computers rely on exact timing and sync bits to maintain data synchronization.

Front 57

Synchronous Data Link Control (SDLC)

Back 57

One of the primary synchronous communication protocols.

Front 58

T1

Back 58

A DDS technology that uses two two-wire pairs to transmit full-duplex data signals at a maximum rate of 1.544 Mbps.

Front 59

T3

Back 59

A communication line that has 28 T1s or 672 channels and supports a data rate of 44.736 Mbps.

Front 60

translation bridges

Back 60

A type of bridge that can translate between network architectures.

Front 61

transparent bridges

Back 61

Generally used in Ethernet networks, these bridges build their bridging tables automatically as they receive packets.

Front 62

virtual circuits

Back 62

A logical sequence of connections with bandwidth allocated for a specific transmission pathway.

Front 63

virtual local area networks (VLANs)

Back 63

A feature of switches that allows network administrators to group users and resources logically, regardless of their physical location.

Front 64

V-series

Back 64

The ITU standards that specify how data communication takes place over the telephone network.

Front 65

What is the most definitive diagnostic tool for thyroid CA?

Back 65

Thyrogen