No Media in the call forwarding and transfer

[Yenosh]

Hi All,

During the call forward and transfer , no audio in the call. During the call with SBC they are saying separate invite has been sent in separate call leg. How we can avoid sending invite in separate leg.

Best Regards,

Yenosh

[Maren Mahoney]

It sounds like your call transfers are generating a new INVITE instead of a REFER. Take a look at these docs as a starting point for what might be happening:
SIP Call Transfer 

Cisco Unified Border Element (Enterprise) SIP Support Configuration Guide - Chapter: Dynamic Refer Handling 

Maren

[Sadav Ansari]

Mainly the Media negotiation issue in these cases so collect the debug on gateway and check then calling party  and final called party codec for the transfer or forward call.

Pls rate if its “Helpful”. If this answered your question pls click “Accept as Solution”.

[Yenosh]

During the troubleshooting, We identified provider is not sending RTP packets prior the call to be connected . So created  SIP profile with Early offer "MTP inserted when needed" This fix the issue with call forwarding.

But we still have issue with call transfer, during this I have not seen 200 ok in not coming to call manager after few seconds cm sending cancel, is there any way to fix.

[Roger Kallberg]

Have you checked the information given by @Maren Mahoney? If you have and still don’t get it to work please post your configuration from your SBC and the output of debug ccsip message as attached files so that we can check.

[Yenosh · Accepted solution]

Hi All,

Thanks for your suggestions.

We did identify the problem, from ccm logs we identified 

looks like SBC or the provider didn’t stream any RTP packets hence no audio. to fix this issue we have created  new SIP profile with early offer : insert MTP if needed" and assigned it to trunks in leaf cluster.

Best Regards,

yenosh