183 progress before OCS lookup RRS feed

  • Question

  • Does anyone know why the Mediation Server would return a 183 message to a gateway, before it does a look up?  OCS ultimately returns a 404 message.  But, the 183 causes an issue in the gateway.  The gateway would have re-routed the call with the 404.

    Call flow: T1 > gateway > Mediation > OCS

    Thursday, June 4, 2009 6:56 PM

All replies

  • Hi Kc,

    From my understanding 183 can be sent when a call is yet to be classified. So it is neither completed or connected but in progress. The behaviour you describe is acceptable and the fact your gateway struggles with this is surprising as it should still reroute the call once it gets the 404 message. Is there something in particular in an RFC you think this doesnt comply with?

    Thursday, June 4, 2009 8:20 PM
  • The 183 changes the state of the call.  I have to dig further, but OCS may have found a match (MOC), and attempted to reach the client.  I need to find out if the MOC is being fwd'ed to an endpoint that eventually fails.

    When the same call is made, to a bogus number, there is no 183 sent.
    Thursday, June 4, 2009 10:14 PM
  • I see a 183 imessage n the testing I have completed. You may want to ensure that the bogus number you send is in a E164 format like an unallocated number in the range you are using to ensure you are getting a true reflection of the intended behaviour. A certified gateway should be able to reroute your call should it get the 183-->404 message flow. What is the gateway you are using?

    Friday, June 5, 2009 3:14 PM