Navigation: Fault Management > Troubleshooting Guide > Trunk Faults > Background >
Channel associated signaling (CAS) indicates that the signaling and voice are transmitted in the same channel. R2 signaling is the CAS.
Signaling Process
An peer user (number 8000) calls an intra-office user (number 7000). Figure 1 shows the normal signaling process.
Figure 1 Normal signaling process
The following describes the signaling process:
1.An peer user calls an intra-office user. peer device sends a seizing signal.
2.unified gateway returns a seizing-acknowledgement signal.
3.Soft Corequests the calling and called numbers from peer device, and then peer device sends the numbers to unified gateway.
4.unified gateway sends status information about the intra-office user to peer device.
5.If the peer user is available, unified gateway sends a response.
6.The intra-office user talks with the peer user.
7.The intra-office user hangs up. unified gateway sends a CALLEDHANDHOOK message.
8.The peer user hangs up. peer device sends a CALLERHANDHOOK message. The talk ends.
Parent Topic: Background