No Ringback from PSTN tranfers AA Unity

[servicios_ciscon2]

Hello team

I have this problem that I have not been able to solve.

PSTN calls enter AA Unity and dialing an extension does not give Ring tone, silence is heard.

I already validated MRGL with ANN and it is OK, I already validated MTP on the CUCM-UNITY and CUCM-CUBE trunk and OK but the problem persists.

The call flow is:       PSTN - sip trunk - CUBE - sip trunk - CUCM - sccp - AA UNITY.

I hope someone can contribute more ideas.

Tks.

[Leonardo Santana]

Hi,

The ringback works for inbound calls to IP Phones?

If you make an internal call to the AA did you hear the ringback?

Regards

Leonardo Santana

[servicios_ciscon2]

Hi Leonardo

The ringback works for inbound calls to IP Phones?

Not from PSTN.

If you make an internal call to the AA did you hear the ringback?

Yes, from internal extensions if you listen, the problem is with calls from PSTN.

Regards

[Leonardo Santana]

Hi,

Collect the CUCM Traces, IPVMS Traces on your CUCM and debug ccsip messages for this call.

Regards

Leonardo Santana

[Scott Leport]

Hi,

Have you seen this thread from several years ago. It’s quite lengthy, but a lot of useful content and various suggestions. Definitely worth checking out! 

https://community.cisco.com/t5/ip-telephony-and-phones/no-ringback-from-sip-provider-after-unity-transfer/td-p/2510422/page/4

[servicios_ciscon2]

Yes, I had already read it and performed several validations such as validating ANN in MRGL, the local network is OK, but the problem continues.