H.450.x ASN.1 Modules
Markku Korpi
korpim at SBS.DE
Sat Sep 20 14:08:19 EDT 1997
Pete and all,
two comments on this mail:
>
> 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-UU-PDU ::= SEQUENCE
> {
> 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,
First:
I must have missed the "dummy" parameter before. I assume the need for
an empty parameter comes from supplementary services, and I suggest to call
it "empty NULL" (this is not an implementation but a standard after all)
and to describe it somewhere in H.225.0. Searching through the document,
the ASN.1 was the only place where "dummy" was used.
(Should I be saying something about puzzles right now? :-)
> 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.
>
Second:
Overall, I agree with the mail from Ernst Horvath on this issue: we should
not add such functionality to H.225.0, not even to version two.
Joerg
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