I have some issue with Icoming call with SIP protocol. I have notice that those sometime my gateway released code 404 to my provider after receiving their Incoming call. I have test the same number from same gateway but the call always get thru with any issue.
I would attache the call trace from my provide IP:10.0.0.193 to number 24285592450509 on my gateway 22.214.171.124 which reased code 404 to them as below.
Note: Not all the time call to particular 24285592450509 and returned code 404 to them but some call were success.
And the atteche is include the successful call and with the call which send code 404 between 10.0.0.193 ----> 126.96.36.199.