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The below information is assuming that you can make outbound calls (where only inbound calling is an issue)
If both inbound & outbound calling is an issue, please visit the following page for assistance:
-> PRI- PRI Down
A very quick way to diagnose inbound calling issues/Disconnect is to take a line trace.
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A successful call will include all of the following messages in this order:
SETUP | Caller sends a SETUP to the Switch |
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CALL PROCEEDING | If the SETUP is OK, the Switch sends a CALL PROCeeding to the Caller, and then a SETUP to the Receiver |
ALERTING | The Receiver gets the SETUP. If it is OK, then it rings the phone and sends an ALERTING message to the Switch, which the forwards theALERTING message to the Caller |
CONNECT | When the Receiver answers the call, it sends a CONNECT message to the Switch which forwards the CONNECT to the Caller |
CONNECT ACKNOWLEDGE | The Caller sends a CONNECT ACKnowledge message to the Switch, which then forwards the CONNECT ACKnowledge to the Receiver |
DISCONNECT | Whichever party wishes to disconnect the call sends a DISCONNECT message to the Switch, which then forwards the DISCONNECTmessage to the remote party |
RELEASE | When the DISCONNECT messages are received by any recipient, it disconnects the call from its side, and sends a RELEASE to the Switch, which forwards it to the other side |
RELEASE COMPLETE | The party who receives the RELEASE sends a RELEASE COMPLETE to acknowledge the end of the entire call |
NOTE* PROCEEDING/PROGRESS/ALERTING messages are optional.
Also, the CONNECT ACKNOWLEDGE message is only sent from NET to CPE (inbound calls from telco).
So for calls made from CPE to NET (outbound calls), the CONNECT message is the last message before
call is considered “up”