3rd Party SIP Phone problem

[gavinr98]

Hopefully someone can help with an issue we are having. We are currently on CUCM V10.5 and everything is working just fine. We are implementing a new video conferencing system which allow SIP activation on call manager. The devices are registering fine and I can call any extension internally and I can call out of the office with no issues. The problem is when I try and dial an extension in a remote office, the phone will ring, but as soon as I answer it will just drop. If I do not answer the call, it will go to voicemail and I can leave a message. This is happening on all the remote offices that we have and the main office as well. I am not sure if this is a configuration on the call manager or not. I am using the same configuration that the cisco conference phone is using and that has no problem calling between sites. If anyone has any clues as to why this is happening that would be great. Also is there some way to monitor the call to see why the call is dropping as soon as the phone is answered.

Any help would be greatly appreciated.

Thanks,
Gavin

 

[gnrslash4life]

I would start by pulling the CM trace files and looking in there.

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE

 

[gavinr98]

I pulled the logs from the CM and I see the following errors ...

1 --- (47) Resource unavailable, unspecified. Explanation: A resource unavailable event occurred and no other cause in the resource unavailable class applies.

I am also seeing

SIP/2.0 503 Service Unavailable

Any ideas as to what might be causing the problem?

Thanks
Gavin

 

[gnrslash4life]

The call is using different codecs and its trying to invoke a Transcoder and cannot. I would look at the MRGL of both endpoints to start with.

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE