Call PSTN no ringback

Unanswered Question
Jul 28th, 2009

Hi NetPro

I have a h323 gateway whit 1 E1 to PSTN, when i call at number1 have ringback and call it's OK, the same when i call at number2, 3, 4, 5, but when i call at numer10 the call don't have ringback but the call establish OK, call again at number1 and have ringback but call at nuber10 and dont have ringback.

any idea?

the call control is CUCM 6.1.

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Paolo Bevilacqua Tue, 07/28/2009 - 11:06

Take "debug isdn q931" with "term mon", see if you can relate the problem to one or more particular B chanell.

After you're positive about it, complain to telco and be prepared to prove your point stongly.

jmecklenburg Tue, 07/28/2009 - 11:27


Attach the debug and first call don't have ringback, and the second have ringback.

the problem is the gateway configuration or TELCO?


Paolo Bevilacqua Tue, 07/28/2009 - 14:15

Telco has not sent ALERTING for the 1st call, so no ringback.

Search "troubleshooting ringback" for suggested workarounds.


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