3905 Phones Registration issue

[haithamnet]

Hello,

We have installed Cisco CUCM 9.1. We are experiencing a strange behavior  with IP phones 3905 which are randomly Registered/Unregistered with the  first and the second CUCM Subscriber (sometimes with the third CUCM Subscriber). The problem is that we are encoutering this issue with phones of the remote site (there is no problems with the HQ phones).

I don't think that the problem is related to the network (LAN/WAN) because we tested a 7911 phone (using SIP firmware too) which is functionning perfectly.

Have you any idea about this ?

I joined a trace collected from a 3905 phone's console :

CUCM :

- version 9.1.1.20000-5

- CUCM Group : SUB1 (192.168.150.2), SUB3 (192.168.150.4), SUB4 (192.168.150.5)

SRST Gateway :

- IOS version : 15.3(2)T

- IP@ : 10.54.1.95

IP Phone 3905 :

- Protocol : SIP

- Firmware : 3905.9-2-2-0

- IP@ : 10.54.1.82

[aelkhalkhali1]

Hi,

did you solve this problem, coz i have the same symptom

thanks

[AVi47]

Correct. Problem was solved.

[Silvano Ferreira de Souza]

Someone managed to solve this problem that happens with the 3905 IP phone?

[andrey.khegay]

According to https://bst.cloudapps.cisco.com/bugsearch/bug/CSCue97809/?rfs=iqvred it's a bug CSCue97809.

Symptom:
3905 SIP Phone is not registering with SRST Router once CUCM becomes unrechable.

Conditions:
3905 using firmware 3905.9-2-2
CUCM: 7.1.5
IOS: 15.2(2)T1
Two or more CUCM Servers inside the CCM Group assigned to the phone Device Pool.

Workaround:
none

In my lab I use 9-4-1 and everything works fine

[Slavik Bialik]

I had the same issue 2 years ago. But it wasn't about the SRST, it was about a MTU configuration on the remote router. The MTU that was configured was too low as far as I remember, and 3905 phone was sending his TCP messages with a DF flag (Do not fragment) so the router was throwing all "big" messages.

[Silvano Ferreira de Souza]

Hi Guys

I just did  the firmware upgrade to CP3905.9-4-1SR2-2 and solved my problem.  CDP time is default on all switches and all working fine.

Thanks everyone.