Cache
Part of your computer's memory. The larger the cache, the better the performance.
CAD/CAM
Computer Aided Design/Computer Aided Manufacture.
Call Forwarding or Rerouting
Incoming calls can be rerouted to any other phone or mobile phone.
CLIR
Call Line Identification Restriction.
Call timer
Tells you how long each call lasts on the phone's display.
Call Transfer
Also referred to as call forwarding. Allows incoming calls to be automatically forwarded to a defined number.
Caller List
List of unanswered ISDN callers.
CAPI
Common ISDN API. Interface standard used to access ISDN equipment connected to basic rate interfaces (BRI) and primary rate interfaces (PRI).
Care-of-Address
A temporary IP address for a mobile device, the COA enables message delivery when the device is connecting from outside its home network. The care-of address identifies the device's current point of attachment to the Internet and makes it possible to connect from a different location without changing the device's permanent IP address: messages sent to the known permanent address are rerouted to the care-of address while the recipient can be reached there.
CPS
Carrier Pre-Selection. It is a service that allows you to route your outgoing calls through the local BT exchange rather than having to program your telephone system or dial a prefix.
CCIR
International Radio Consultative Committee. Now the ITU-R.
CCM
Call Centre Management.
CDMA
Code Division Multiple Access. Spread spectrum data transmission technology used by cellular telephone systems.
CE
European CE mark, devised as a means to facilitate the free movement of goods throughout Europe.
CELLSTREAM
Integration of voice, video and data over a single access. Voice over IP.
CELP
Code Excited Linear Predictive. A voice compression algorithm that achieves high compression rates along with good quality voice reproduction. See also LD-CELP.
Checksum
A number produced by an algorithm designed to establish whether errors have been introduced into a data stream.
Chrominance
The part of a composite video signal that contains the colour information about the image.
CIF
Common Intermediate Format. An internationally recognised standard for the resolution of transmitted video images. 352 by 288 resolution.
Circuit switched
Automatic Gain Control. A method of automatically controlling the gain of an audio path. May be used as a sub component of an audio echo canceller.
CLI
Calling Line Identity. The network will transmit the telephone number of the call originator to the recipient.
CIDR
Classless Inter-Domain Routing allocates and specifies the Internet addresses used in inter-domain routing more flexibly than was possible with the original system of IPv4 address classes. As a result, the number of available Internet addresses has been greatly increased.
CLI
Calling Line Identify. This is a telephone system/service feature that permits users to see the telephone number and/or name of the caller.
Codec
COder/DECoder. Algorithm used to compress and decompress media streams such as audio and video.
Compact PCI
PCI bus contained within a Eurocard form factor. More rugged and secure than the standard PCI cards used in desktop computers.
Compression
The process of reducing the amount of data that is transmitted or stored by a system. Compression can either be lossy or loss-less. The former does not allow full reconstruction of the original data but usually gives more efficient compression.
Communication server
Also called a "call server" or "softswitch", this element is the brains of the network, providing call control, gateway control, service intelligence, and other centralised functions.
Conference Call/Three Way Calling
Function which allows several parties to be interconnected for a communal discussion or "conference".
Continuous Presence
A technique that combines two or more video images for simultaneous transmission or display. Used in multipoint conferencing.
Core switches and routers
These elements provide connectivity to the public network.
Correspondent Node
A peer node with which a mobile node is communicating. The correspondent node may be either mobile or stationary.
CRC
Cyclic Redundancy Check. An error checking method designed to improve the reliability of transmitted data.
CSDN
Circuit Switched Digital Network.
CTI
Computer Telephony Integration. Connection of the telephone system and LAN allowing information to be passed from the telephone system to the LAN.
