电信专业英英词典C-9（在线收听）

　　CPU

　　central processing unit

　　Cross Connect

　　1.in a premises distribution system, equipment used to terminate and administer communications circuits. In a wire cross connect, jumper wires or patch cords are used to make circuit connections, between horizontal and backbone wiring segments. 2. in transmission systems a patch panel for connecting circuits.

　　CSDC

　　circuit-switched digital capability

　　CSMA/CD

　　Carrier sense multiple access with collision detection; a local area network contention based access control protocol technique by which all devices attached to the network "listen" for transmissions in progress before attempting to transmit themselves and, if two or more begin transmission simultaneously, are able to detect the "collision". In that case each backs off (defers) for a variable period of time (determined by a preset algorithm) before again attempting to transmit. (Defined by the IEEE 802.3 standard).

　　CSR

　　Centrex station rearrangement

　　CSU

　　channel service unit

　　Customer Premises Equipment

　　Customer Premises Equipment is all telecommunications terminal equipment located on the customer premises. except coin operated telephones.