TSP Edge User’s Manual
40-400-00065, Rev. E
159
CAMA Trunk
A specialized trunk that routes between an originating switch and the
switch with the CAMA system. A CAMA trunk provides an answer
state back to the originating office as an acknowledgement of receipt of
the dialing information, not as an indication of far-end answer.
CAS
Channel Associated Signaling. An E1 signaling option that is used for
analog traffic and utilizes a common channel of the E1 to provide
signaling.
Channel
A means of one-way transmission. Each TSP Edge module has a set
number of logical channels for each port. Each channel can be assigned
a phone number, digits to transmit
(T1/E1 only) and an audio message.
Clear Channel
A channel with no framing or control bits that supports a 64 Kbps
connection with another channel. Also known as a “nailed up” end to
end digital connection.
CLIP
Calling Line Identification Presentation. A supplementary service that
provides the calling party’s number to the called party.
Clock
See Internal Clock and External Clock.
CO
Central Office. The location of the last major switching point in the PSN
before the connection is made to the customer premise.
Companding
The process of compressing the amplitude range of a signal for
economical transmission and then expanding it back to its original form
at the receiving end.
CPE
Customer Premises Equipment. Term used to describe telephony
equipment that resides on the customer’s premises.
CRC-4
An E1 error detection option.
CSU
Channel Service Unit. CPE used to terminate T1 services at a customer
site. Also known as a DSU (Data Service Unit) and commonly called
CSU/DSU.
D bit
The least significant bit of the 24th frame, used in ESF format only, to
send signaling information.
