Disclaimer - if I have misunderstood your problem description then please disregard my response below I'm going to take a stab at this and say the problem you are having is with your provider rejecting the forwarded calls with an "unallocated number...
What do the CUCM traces say? You can also enable cch323 debugging on the gateway to see if CUCM is sending the disco first. In my experience esource unavailable usually indicates a DSP, MTP, Xcoder issues that I have seen. Fast Start enabled?You c...
I had this same exact issue with a SIP SP provider doing G711u. As Felipe mentioned the problem was on the carrier side. They are expecting the the UC520 to send RTP but the UC520 is only "relaying" the media it recieves. Since the SP was not send...
Over 2 months since I first opened a TAC case about this problem. I'm pretty sure the natives have already drawn and quartered me, but my pergatory is dealing with the same issue and waiting for Microsoft to patch
