CUCM 12.5 BIB secure audio recording, SIP BYE immediately after ACK

cehopkins1010 · ‎02-22-2021

Hello all-

I have a situation trying to record a call via BIB media forking to a third-party recording application. The environment is using secure audio, the phones register correctly and the call audio is secured as expected. Certificates have been installed on the CUCM and recording servers successfully, at least with no errors reported anywhere that I have found.

The recording server sends an OK message with SDP, and CUCM sends back an ACK with crypto information as expected. Immediately after the ACK, however, CUCM sends a BYE message, killing the audio stream to the recording server. The negotiated codec on the call is G.711 mu-law, so codec problems do not appear to be the issue.

I have attached a text file containing the SIP traffic between CUCM and the recording server. I have not been able to find a resolution over a couple months' worth of searching online or experimenting with various settings. If anyone has any thoughts or insights, they would be greatly appreciated!

Best regards,

Clay H.

dstaudt · ‎02-23-2021

I'm not sure I would have expected your side to re-send SDP in the 200 OK response to the CUCM UPDATE, but don't know for sure if that's a real SIP issue (not a deep expert) or something CUCM doesn't like/expect. It might be interesting to have the recording target be a regular Cisco phone, pick up the recording call, and compare the SIP signaling (assuming the test works.)

Most likely will need to have the CUCM-side internal logs reviewed to understand what the root cause might be in detail - I would suggest opening a ticket with DevNet Developer Support: DevNet Support

To get a head start, I would include a network packet capture of the scenario (e.g. using Wireshark) along with the CUCM SDL/SDI logs for ~10 minutes before/after the test, i.e. per: https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/200787-How-to-Collect-Traces-for-CUCM-9-x-10-x.html

cehopkins1010 · ‎02-24-2021

Hi dstaudt-

Thank you for your reply and the idea of targeting a phone, I will give that a go to see what the SIP looks like compared to the recorder. I had sent the SDP on the OK to the UPDATE as a test only. It must not matter, because the behavior is the same regardless of the existence of SDP on that OK message. I'll open a ticket with Dev Support as well.

Thanks again!