CUCM 10.5 2nd call goes to VM

[cmite]

Hello ... for CUCM 10.5. When a user is on a call, a second call goes straight to VM without ringing. Also, when a users puts a call on hold, the call drops on resume. Max calls set to 6 and Busy Trigger set to 2. About to dive into call trace but not sure what to look for. Any ideas? Thanks. 

[Vineet Kumar Gautam]

HI,

Few questions?
1. IS this happening with all the users? If happening with multiple users then any similarities like same model of phones, firmware location etc?

2.Was it working before or is it a day 1 issue?

Few suggestions

1. Try to remove the callforward busy setting >> save apply config >> re-add the call forward busy >> save and then test

2. Delete and re-add one DN and test

3. Is it possible user is pressing DoNot Disturb option?

4. Try restarting call manager service and then test.

If any of the above does not help I need callmanager logs to look into the traces if you can collect them and provide me.

-Vineet

[cmite]

Thank you, Vineet. This issue is widespread impacting all phones - 7942s and 7962s. I inherited this issue and trying to resolve it. Per the only tech still around who's been managing this voice system, there have been no changes or upgrades other than migration to SIP around the same time it started happening, he thinks. I collected a trace and see the ring but it goes straight to VM. I didn't think it's a SIP issue because the same thing happens with internal calling - DN to DN. I'll apply your suggestions to one DN and let you know.

Thanks again.

[cmite]

Hi Vineet... we did several tests - added a new, unused DN, removed a DN completely from CCM and re-added it, removed CF busy, saved, and re-added. Was about to configure trace and notice Call Manager and CTI Manager services are down on the Pub but up on both Subs. Checking with an engineer who worked on this before to see if that was done intentionally.  

[cmite]

Looks like disabling Call Manager and CTI Manager on the Pub when there are two or more subs is Cisco's best practice. I'll collect the traces and share with you. Thanks. 

[cmite]

Hi Vineet,

Thank you for volunteering to help. After some troubleshooting and testing, we realize the problem has nothing to do with multiple calls. Any incoming external call, when placed on hold either drops immediately or drops when the resume button is pressed logging SIP/2.0 500 Internal Server Error message. I've already tried changing SIP Rel1XX Options from disabled to "Send PRACK for all 1xx messages" and restarted the SIP profile. I've attached the SIP trace with some sensitive data sanitized.

Thanks again. 

[cmite]

Sorry for the delayed update. This was an asymmetric routing issue caused by the CUBE communicating with a CUCM subscriber over SD-WAN with two active/active circuits. SIP messages were routing over both circuits and arriving at the CUBE out of sync. Resolution: add session transport tcp on the dial-peer facing CUCM to make the communication reliable.