Incoming call but UCM does not respond


Hello everyone.
I have a question need you support.
I use UCM6510 for some calls but ucm has no response.
So the provider IP waits for a long time to cancel?
UCM sends 100 trying but doesn’t send 200 OK?
I sent log and image, Pls check file capture log help me.
Thank you very much
Sorry for the bad English

caller (1.3 KB)


Please define the network setup and the UCM network mode. I see the provider is on a different subnet, so my guess is that for whatever reason they are not seeing the UCM response and timing out.


Hi Ipneblett.
Not every call happens that way.
Sometimes this situation happens
I do not why
Thank you


It is hard to say, but after 100 there should be 180 ring or 183 not 200 OK (unless it go to IVR/queue).

It was catch on UCM ?


Yes, my call to IVR. But I didn’t hear the IVR and the call ended


Would need to see the details in the pcap.


Yes PCAP only have SIP, rtp is missing.
No idea what going there.