Γλωσσάρι Δικτυακών Ορολογιών
Ταξινομημένα προς το παρόν Κατά τελευταία ενημέρωση (αύξουσα) Ταξινόμηση χρονολογικά: Κατά τελευταία ενημέρωση
Category 1 cablingOne of five grades of UTP
cabling described in the EIA/TIA-568B standard. Category 1
cabling is used for telephone communications and is not
suitable for transmitting data. | |
Category 2 cablingOne of five grades of UTP
cabling described in the EIA/TIA-568B standard. Category 2
cabling is capable of transmitting data at speeds up to 4
Mbps. | |
Category 3 cablingOne of five grades of UTP
cabling described in the EIA/TIA-568B standard. Category 3
cabling is used in 10BASE-T networks and can transmit data at
speeds up to 10 Mbps. | |
Category 4 cablingOne of five grades of UTP
cabling described in the EIA/TIA-568B standard. Category 4
cabling is used in Token Ring networks and can transmit data
at speeds up to 16 Mbps. | |
Category 5 cablingOne of five grades of UTP
cabling described in the EIA/TIA-568B standard. Category 5
cabling is used for running CDDI and can transmit data at
speeds up to 100 Mbps. | |
CDCarrier Detect.
Signal that indicates whether an interface is active. Also,
a signal generated by a modem indicating that a call has
been connected. | |
cellThe basic unit for ATM
switching and multiplexing. Cells contain identifiers that
specify the data stream to which they belong. Each cell
consists of a 5-byte header and 48 bytes of payload. | |
channelized E1Access link operating at 2.048
Mbps that is subdivided into 30 B-channels and 1 D-channel.
Supports DDR, Frame Relay, and X.25. |
channelized T1Access link operating at 1.544
Mbps that is subdivided into 24 channels (23 B-channels and
1 D-channel) of 64 Kbps each. The individual channels or
groups of channels connect to different destinations.
Supports DDR, Frame Relay, and X.25. Also referred to as fractional
T1. |
CHAPChallenge Handshake
Authentication Protocol. Security feature supported
on lines using PPP encapsulation that prevents unauthorized
access. CHAP does not itself prevent unauthorized access, it
merely identifies the remote end. The router or access
server then determines whether that user is allowed access.
| |
CIDRClassless interdomain
routing. Technique supported by BGP4 and based on
route aggregation. CIDR allows routers to group routes
together in order to cut down on the quantity of routing
information carried by the core routers. With CIDR, several
IP networks appear to networks outside the group as a
single, larger entity. |
coaxial cableCable consisting of a hollow
outer cylindrical conductor that surrounds a single inner
wire conductor. Two types of coaxial cable are currently
used in LANs: 50-ohm cable, which is used for digital
signaling, and 75-ohm cable, which is used for analog signal
and high-speed digital signaling. | |
CODECCoder-decoder.
Device that typically uses PCM to transform analog signals
into a digital bit stream, and digital signals back into
analog. |
collisionIn Ethernet, the result of two
nodes transmitting simultaneously. The frames from each
device impact and are damaged when they meet on the physical
media. | |
collision domainIn Ethernet, the network area
within which frames that have collided are propagated.
Repeaters and hubs propagate collisions; LAN switches,
bridges and routers do not. |
community stringText string that acts as a
password and is used to authenticate messages sent between a
management station and a router containing an SNMP agent.
The community string is sent in every packet between the
manager and the agent. | |
compressionThe running of a data set
through an algorithm that reduces the space required to
store or the bandwidth required to transmit the data set.
|
core routerIn a packet-switched star
topology, a router that is part of the backbone and that
serves as the single pipe through which all traffic from
peripheral networks must pass on its way to other peripheral
networks. | |
COSClass of service.
Indication of how an upper-layer protocol requires that a
lower-layer protocol treat its messages. In SNA subarea
routing, COS definitions are used by subarea nodes to
determine the optimal route to establish a given session. A
COS definition comprises a virtual route number and a
transmission priority field. Also called TOS (type of
service). |
CRCCyclic redundancy check.
Error-checking technique in which the frame recipient
calculates a remainder by dividing frame contents by a prime
binary divisor and compares the calculated remainder to a
value stored in the frame by the sending node. |