GCL ftp site has got back to operation

Sakae Okubo okubo at GCTECH.CO.JP
Wed Dec 3 16:23:04 EST 1997

Dear Pete and all others !
My additional comments are below:

>3. H.225.0 Annex H - ASN.1
>All ,but UI-UUIE, XXX-UUIE messages have callIdentifier field.

We agree with Pete's proposal. It is more general but requires more changes in the standard. Let fix it one way or another, but till Geneva!
>4. H.450.2 Clause
>This clause is talking about Call Transferring in case of GK Call
>Routed model and both Q.931 Signaling and H.245 protocol are "routed"
>by the GK. According to H.323V.2 GK's Call Routed model where Q.931
>Signaling is routed by the GK, but H.245 messages flow directly is
>legal and more efficient. It seems that the clause above doesn't cover
>this case. In order to provide a working solution for this case, an
>additional OPTIOANAL field "h245Address" should be added to
>Facility-UUIE message ...

Three things on this:
Firstly, Pete, you are right about the "future study". Still this mode is more efficient and we shouldn't cancel it without serious considerations. In this case (of H.450.2) with this optional  field we could support it. Do we want  to cancel the possibility of using this mode without even studying it ?
Secondly, the facility message, described in H.450.2 section, may contain Facility-UUIE as a part of it. Currently this Facility-UUIE is empty, but it can be used and have a new h245Address field.
Thirdly, I will try to explain the relevant scenario using H.450.2 terminology.  Suppose, A and B are in the GK routed call, while H.245 and UDP streams flow directly between them. All "transferring logic" is performed by the GK on behalf of B. None of the mentioned messages (specifically CONNECT message) reaches B. Still, when the call is transferred from A to C, B has to receive (a new) H.245 address of C. The proposed way to receive it, is by means of  FACILITY message containing Facility-UUIE. Pay attention that B, who doesn't perform the "transferring logic" itself, upon arrival of the FACILITY message containing a new H.245 address, has to close the old H.245 channel and open a new one (towards C).

(I am starting to enjoy it, but I am serious.)

>Orit Levin
>RADVision Inc.                          E Mail: orit at radvision.com
>575 Corporate Dr., Suite 420            Tel:    201-529-4300 ext. 230
>Mahwah, NJ 07430                        Fax:    201-529-3516

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