call transfer failed frequent on CUCM 9.1.1.20000-5 , but after restart the server it works

[Qiyu Bao]

hi, guys

    we meet trouble on the feature of call transfer 

    Currently our ip phone system existing a problem. All external phone call unable transfer to extension when they dial the extension number.

    After we reboot the cucm server, this issue will be fixed. But this issue frequent occurrence.

    the version is 9.1.1-20000-5

    the phone types we deployed are 7942, 7960, 7937, 8831

    the issue come up every week , and have been for 2 months, just reboot the server,  the call transfer get working normally 

    shall i need have a try to upgrade the version of CUCM ?

[Rajan]

Hi Qiyu,

I am not sure whether this issue is related to your version. But definitely this version (9.1.1) had lot of bugs/issues and it is recommended to upgrade to any of the latest 9.1.2 versions or to 10.x/11.x if possible.

HTH

Rajan

[Rajan]

Parallely troubleshoot this issue by collecting traces to find the cause for this.

[Manish Gogna]

Hi Qiyu,

Since external calls are affected they are most likely coming in thru a SIP or H323 gateway/trunk. If supplementary functions like transfer are not working then this could be due to MTP not getting allocated correctly. As you mention that the issue is fixed by restarting cucm so it looks like a MTP leak issue. I would suggest upgrading cucm to at least the ;latest 9.1.2 version as Rajan suggested and also ensure that all MTP resources are registered and working fine.

Manish