Common channel
signalling (CCS)
The packet-switched
signalling network is separated from circuit switched connections. Consequently:
In practice, CCS
= SS7 (except maybe North America).
In Finnish: CCS
= yhteiskanavamerkinanto (YKM)
Exchange
Exchange
signalling possible anywhere anytime
Database
1) Signalling to/from databases is possible anytime.
2) End-to-end signalling is possible before call setup and also during the
conversation phase of a call.