Karl,

Your 2nd option looks good to me too...

Regards,

Pete ================================= Pete Cordell BT Labs E-Mail: pete.cordell@bt-sys.bt.co.uk Tel: +44 1473 646436 Fax: +44 1473 645499 =================================

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From: Karl Klaghofer[SMTP:karl.klaghofer@MCH.PN.SIEMENS.DE] Sent: 03 December 1997 09:40 To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Limitation of nonStandardData and other issues related to H.450

Some comments related to H.450.x have been placed to the reflector the last days.

1. H.450.2 Clause 10.5 (item 1 of Levin Orit's comments, dated Dec.1)

I agree, 2nd paragraph, third line: ...and conferenceGoal="invite"... should be deleted.

2. H.450.2 Clause 10.6.1.1 (item 4 of Levin Orit's comments, dated

Dec.1) The procedures defined for this gatekeeper active transfer case right now are very much based on the gatekeeper having H.225 as well as H.245 control (i.e. H.225 as well as H.245 routed via gk). The model you are referring to (H.225 via gk; H.245 direct routed) was not investigated in conjunction with active gk transfer, since this model is (as Pete sayd) still marked as "for further study" in H.323V2 ! Using the direct H.245 model in conjunction with active transfer by gatekeeper would introduce a further, alternative method of handling the logical channel closing and reopening issue at the transferred endpoint B. Remark: In Sunriver September meeting, the goal was to have just one method (we picked the "empty terminalCapabilitySet" method and dropped the "requestChannelClose with reopen" method in order to reach this goal. Proposal for further proceeding: First the H.245 direct model has to be investigated for H.323 (maybe H.323V3). Then, H.450.2 (maybe V2) might be updated to get this model also to work for active gk transfer.

3. Limitation of nonStandardData (Comment from Pete Cordell, dated

Dec.2) Currently we have in H.450.x constructs like the following:

argumentExtension CHOICE {extensionSeq ExtensionSeq, nonStandardData NonStandardParameter } OPTIONAL

ExtensionSeq ::= SEQUENCE OF Extension{{ExtensionSet}}

ExtensionSet EXTENSION ::= {...} -- Actual values defined by individual manufacturers

This means: either one value nonStandardParameter or a SEQ of an arbitrary number of values of type Extension may be inserted.

1st possible change: allow more than one nonStandardParameter:

argumentExtension CHOICE {extensionSeq ExtensionSeq, nonStandardData SEQUENCE OF NonStandardParameter } OPTIONAL

which means either a SEQ of Extensions or a SEQ of NonStandardParameter may be inserted. This 1st possibility would be a H.450 change corresponding to Pete's proposal for H.225/H.245.

2nd possible change:

argumentExtension SEQUENCE OF MixedExtension OPTIONAL

MixedExtension ::= CHOICE {extension Extension{{ExtensionSet}}, nonStandardData NonStandardParameter }

This 2nd possibility would be a H.450 change corresponding to Pete's proposal for H.225/H.245, which adds a further dimension of allowing mixing of any number of NonStandardParameter and ISO like Extensions within one pdu. This may have advantages e.g. in the case that an ISO like Extension is contained within a received pdu in a gk and the gk wants to add further extensions of the NonStandardParamter type (or vice versa) to the same pdu. Proposal for further proceeding. The 2nd possibility mentioned above should be added to a H.450V2.

================================================== Karl Klaghofer Siemens AG Munich, Hofmannstr. 51, D-81359 Munich, Germany Dptmnt: PN VS LP3, Building/Room: 1760/455 Tel.: +49 89 722 31488 Fax.: +49 89 722 23977 email: karl.klaghofer@mch.pn.siemens.de ==================================================