IP Phones started rebooting randomly suddenly - CUCM 10.5.2

[eng.sultan.b]

Hi guys,

Suddenly the users are complaining that the phones are rebooting randomly in different time also some users experience this issue more than other.

Also the phones are in different types (9971 - 8961 - 7841 - 6941 and other SCCP types) so this issue is not related to one type.

The cabling are ok so it's not a physical issue.

I thought maybe caused by the firewall because we just replaced the old ISG to Palo Alto but as per the security team they applied the same rules in the new firewall and they don't see any dropped or denied packets.

I checked multiple questions in the forum related to rebooting phones but didn't find anyone got a solution!! :(

We have CUCM v10.5.2 and used it since last year without any issue.

We don't have smartnet to open TAC case so please I need your urgent support in this matter. I need to know how to deeply investigate this issue and if it cause by firewall our network how to prove it :(

Please let me know if you need any further information.

Best Regards,

[Manish Gogna]

In order to nail the issue you need to get a parallel set of packet captures from an IP phone and the CUCM to which it is registered , the packet capture should cover 3-4 minutes prior to the phone getting unregistered to see if the keepalives and keepalive ack's are being exchanged without any drops between the server and endpoints. If you see any of the keepalives or keepalive acks missing in the capture then it will point to an issue on the underlying network.

HTH

Manish

[eng.sultan.b]

Hi Manish,

Thank you for your prompt reply :) I will do packet capture an see.

Best Regards,

[HARIS_HUSSAIN]

You can also analyze the Event Logs to see the Reason Code for Phones Unregistered.

Via RTMT collect below

• Event Viewer-Application Log
• Event Viewer-System Log

Search of the Time Frame and MAC of the Phone which Unregistered.

You will see log as below which also specified the reason for unregsiteration. 

%CCM_CALLMANAGER-CALLMANAGER-3-DeviceUnregistered:

Search for reason code in below document

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/err_msgs/8_x/ccmalarms861.html#UC_CALLMANAGER-4-DeviceUnregistered.

If it is related to Network then you might need a packet capture as well.

Thanks

Haris

[eng.sultan.b]

Hi Haris,

Thanks for the information :)

However, I already checked the logs last week but mostly I found reason code for normal reboot (for example reason 22 for reset command from CUCM ... etc.).

As I said to Manish, I will try to do packet capture and check it.

Thanks again.

[eng.sultan.b]

I don't know what happened but the issue didn't occure again :) Mabye there was a network issue at that time.

However, I noticed that some phones registered to the secondary server in the CM group and when I restarted the phones they registered to the primary server but after some time re-registered again to the secondary server?! Is this also a network issue or there is something else?

Thanks & Regards,

[Manish Gogna]

As long as primary cucm defined in the callmanager group is up and reachable the phones will register to it, in case they r registering to secondary cucm it means the communication between phones & primary cucm is broken due to some reason.