I am having a weird issue where about 40% of EXTERNAL (internal work fine as per customer) calls get dropped when CUC tries to transfer them to a user, Hunt Pilot or External party. This happens both after hours and business hours, so i dont think its related to
Topology: SIP Integration everywhere with G711.(i will confirm the specific versions in a while)
ITSP---->CUBE G.711alaw----->SIP Trunk to CUCM---->CUCM----->2 SIP Trunks to individual CUCs on G.711ulaw---->CUC G.711alaw (plays prompt then transfers)---->back to CUCM to hunt pilot.
Error:
The CUBE shows error code 65(bearer capability mismatch) for failed calls.
Problem Description:(will attach the logs soon)
The Calls hit the CUC and system greeting/prompt is played "wait while we transfer the call" and then the call simply drops.
I opened a case TAC case with CUC team that got transferred to CUCM team who came back saying CUCM is getting this message to drop the call.
The reason they proposed was:
"when CUC tries to transfer CUCM gets a REFER from CUC which CUCM relays to CUBE as INVITE. for successful calls we get a OK response but for unsuccessful calls we get BYE"
I then worked with the CUBE team and was told that the service provider is changing the parateres for the re-invite which is why the calls are being droppped.
"
55 14:59:43.302 INVITE XXXXX6971 W/ SD->
206 14:59:43.310 INVITE 6971 W/ SDP----->
244 14:59:43.314 <-------------100 Trying
257 14:59:43.314 <-------------100 Trying
271 14:59:43.362 <------------180 Ringing
298 14:59:43.362 <------------180 Ringing
315 14:59:43.450 <---------200 OK W/ SDP
419 14:59:43.454 ACK 6971--------------->
437 14:59:43.454 <---------200 OK W/ SDP
470 14:59:43.466 ACK XXXXX6971---------->
483 14:59:45.714 <-INVITE 004161XXXXX W/
550 14:59:45.718 <-INVITE 4161XXXXX W/ SD
586 14:59:45.718 100 Trying------------->
600 14:59:45.770 200 OK W/ SDP--------->
648 14:59:45.774 <----------ACK 4161XXXXX
670 14:59:45.774 <----------BYE 4161XXXXX
687 14:59:45.774 BYE 004161XXXXX-------->
704 14:59:45.778 200 OK----------------->
727 14:59:45.782 <-----------------200 OK
in above call, first INVITE from Telco has codec 8 0 18 96; when Telco responds the RE-INVITE (codec 8 96 19) from CUBE, it has codec 97 96, which causes CUBE not able to find common codec."
I escalated this with the service provider who is reluctant to accept that anything is wrong on their end.
What I do not understand is why is:
1) why does this happen only for call transfer from CUC
2) why only a few EXTERNAL calls.
I understand that at this stage I have not provided the logs and versions for the servers, but any insight on this issue will be greatly appreciated.
