Hi to all, I have a problem transferring calls frrom CTI ports.
Scenario is the following:
- Asterisk connected to CUCM (8.6) via a SIP Trunk.
- Incoming calls from Asterisk are answered and then held on CTI Ports on CUCM.
- Then we make a second call to an IPPhone from the CTI Port where the incoming call is Held.
- When the operator answers the call from the CTI Port, we merge the two calls via a transfer method, so the original incoming call is transferred to the IPPhone, and after this operation comunication is between Asterisk'phone and IPPhone on CUCM.
Sometimes, the last operation (transfer) fails so the two calls aren't merged.
What may it be ?
 
- We 
 
 

We caught a Timeout Exception via JTapi. while it seems that CUCM sends an Internal Server Error to the Asterisk.
On the phone we see only the call from the CTI Port.
I've Attached  SIP trace log captured with rtmt tool.
Thank.

Attachments:

We are going to test connection between two phones. 
Our customer has a very complex infrastructure: there are 2 firewalls between CUCM and Asterisk, so I'm not sure  there isn't network problems. I've asked to the customer to verify his infrastructure.
By the way, I post you a trace where we have tracked a SIP/2.0 500 Internal Server Error. It seems that sometimes CUCM answers with this error.
Thanks for your help. Any ideas is appreciated.

Attachments:

From the pcap, the error UCM returns is Q.850 cause 100:
 
Cause No. 100 - Invalid information element contents [Q.850]
This cause indicates that the equipment sending this cause has received and information element which it has implemented; however, one or more Gelds in the I.E. are coded in such a way which has not been implemented by the equipment sending this cause.
There is an initial invite from Asterisk from 11130151004951@10.129.18.11 to UCM (CTI port?) 110010301@10.120.4.10 which sets up fine, but then there is a re-INVITE from Asterisk for the same call, changing media endpoints and adding PCM a-law media type.  I'm not sure why the Asterisk is doing this, or the exact reason why UCM doesn't like this, but it seems to be problematic.
It would probably take some detailed analysis of the UC Manager call processing logs to determine the exact cause, which I think means we would direct you to open a case with the CDN Developer Services group: http://developer.cisco.com/web/devservices