Page 62 - eBOOK FUNDAMENTAL OF TELECOMMUNICATION NETWORK

Signaling in PSTN is classified into two groups :-

Channel Associated

Signaling (CAS)

Channel Associated Signaling (CAS), where

certain signaling information is associated with the

voice channels over the same transmission

medium.

CAS uses the same channel for signaling and

voice.

Common Channel

Signaling (CCS)

Common Channel Signaling (CCS), where

signaling information from many users is
multiplexed over a common channel and can be

carried separately from the voice traffic.
CCS is a signaling method in which voice signals

and control signals are sent through different
channels.

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