Pete Cordell pete.cordell at BT-SYS.BT.CO.UK
Thu Sep 18 08:47:20 EDT 1997

Dear All,

It has been mentioned that when a gatekeeper performs a re-route it
would be good for the client to know about it.  After much
investigation, there seems to be no message in Q.931 that handles this
case.  In the text that I proposed in Sunriver I suggested that a
Facility message with a H.450 ctComplete should be sent.  However, this
is not much use to an entity that does not support supplementary
services.  Therefore it might be useful to add can extra case to the
H323-UU-PDU to cover this, e.g.:

        h323-message-body   CHOICE
                setup                   Setup-UUIE,
                callProceeding          CallProceeding-UUIE,
                connect                 Connect-UUIE,
                alerting                Alerting-UUIE,
                userInformation UI-UUIE,
                releaseComplete ReleaseComplete-UUIE,
                facility                Facility-UUIE,
                progress                Progress-UUIE,
                dummy                   NULL,
                reRouteIndication       ReRouteIndication
        nonStandardData NonStandardParameter OPTIONAL,
h4501SupplementaryService       SEQUENCE OF H4501SupplementaryService OPTIONAL

ReRouteIndication ::= SEQUENCE
        display         IA5String (SIZE( 0..255) ),
        endpointInfo    EndpointType,

This could then be sent by a gatekeeper when a re-route has been done.

Any comments?

Pete Cordell
BT Labs
E-Mail: pete.cordell at
Tel: +44 1473 646436
Fax: +44 1473 645499

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