07-27-2023 04:37 PM - edited 07-27-2023 04:41 PM
SIP traffic is not working properly, we recently upgraded to PAN OS version 10.2.4-h2 and seeing issues with multiline calls
Steps taken:
ALG is disabled, we have already created SIP-override and RTP override but no luck.
We then did a packet capture and found that SIP traffic flow completes fine and call works fine but when user tries to add any other user, we see a Re-invite from CUCM IP to the device IP generating the call and that traffic is being dropped in the firewall drop.pcap.
Now, as per the wireshark logs, we suspect this to be a MTU issue as payload is around 1511. As a workaround, we have removed information from the SIP profile to reduce it's size and as expected that has resolved the issue. The info I removed is display/party information so effectively I've disabled caller ID.While technically leaving it disabled is not a solution
But this was working fine without any issues on the previous version , so why it is being dropped in drop.pcap now on a higher version.
So, looking for some suggestions or insights if anyone else is facing the same issue.
