7937 conference phones showing CM Down Features disabled

[kim jones]

I continually see the 7937 conference phones re-register for no apparent reason and they will drop calls with the display showing CM Down Features Disabled.  Once the user hangs up from the call and re-iniates it then the call will start but will drop again after a few minutes of talk time.  I also have 7965 phones and these are not experiencing this issue.  The issue will be present for about 1 - 2 days and then go away for about a month or 2 and then start back up.  I have been directed by Cisco to increase the keep alive timers and only have 1 VLAN programmed on the ports for the 7937 but even after making these changes the problem was still present just not as acute.  Any ideas?  All of my phones are connected to CUCM running 8.5.1 via 6509 switches on 10 floors.  I am running the latest firmware on the 7937 phones 1.4(4).

[Chris Deren]

You can review the console logs on the phones for clues.

HTH,

Chris

[kim jones]

We have and they are showing that the TCP connection is dropping.  It also shows that the phone tries to re-register with the subscriber in our DR site but it won't because it is still registered with the subscriber at the main site.

[Youssef Aoufi]

Hi Kim,

I have the exact same problem with the 7937 conference stations.

Have you solved it?

Thank you in advance

[jmjavier]

Hi Kim,

I have the same issue and also running CUCM 8.5.1 with 1.4.4.0 phone load. Upgraded to 1.4.5.7 as suggested by TAC and did not resolved the issue. Did you resolved yours?

Thanks,

Jimmy

[kim jones · Accepted solution]

We use 6509 switches and they were causing some of the issue.  I'm not a network guru so hopefully what I post will lead you in the right direction.  The 6509 were punting...

Also, the 7937 phones should only have the voice VLAN assigned and not voice and data VLAN.

Also, when we ran traces it showed that the phone thought it was losing CDP packets so it would lose connectivity.  This was fixed by applying the firmware 1.4.4.87 (this firmware took care of the CDP and DHCP issues we were seeing.)

There are so many emails but I think I have put all the highlights you will need...if not, my Cisco case number was SR 623039621 if you get in touch with Cisco and want them to check the case notes...it's all there!

Good luck!

[jmjavier]

Thanks for the quick replay, I run this to the TAC engineer handling my case and he confirmed through the logs I provided him that we are hitting the same bug on the SR you listed above. He provided me with the 1.4.4.87 phone load and told me not to worry about the VLANs on the switchport as this engineering special will takes care of the issue (VLAN and DHCP). Again, thanks posting your solution so quicky.

Jimmy

[kim jones]

Awesome!  I'm so glad I could help!

Kim