Gary,

You be the judge:

Summary/H.323v2: "Products claiming compliance with Version 2 of H.323 shall comply with all of the mandatory requirements of this document, H.323 (1998), which references H.225.0 (1998) and H.245 (1998). Version 2 products can be identified by H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 2250 version (0) 2} and H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 245 version (0) 3}."

Assuming this text is normative, H.323v2 uses H.225.0v2 and H.245v3. Period.

IMO, we will be asking for big trouble if we at some point decide that one can mix and match versions and even use subsets or supersets of a particular version. Whatever interoperability problems we have now will be magnified many times over if we head down that slippery slope.

Paul Long Smith Micro Software, Inc.

-----Original Message----- From: Gary A. Thom [SMTP:gthom@DELTA-INFO.COM] Sent: Friday, January 29, 1999 1:37 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Relationship of H.323 and H.245 versions

One more question????

> Dave, > > Sorry, but I won't be in Monterey. > > I agree with what you say, except that I would go further and state that there > is always a one-to-one mapping between H.225.0 and H.245 protocolIdentifiers > via H.323. For example, > > H.225.0v1 => H.323v1 => H.245v2 and H.245v2 => H.323v1 => H.225.0v1 > H.225.0v2 => H.323v2 => H.245v3 and H.245v3 => H.323v2 => H.225.0v2 > > This is already implied by the Summary section of H.323 starting with version > 2. I think it's clear, but you could add clarification text if you like. IOW, > for example, an EP cannot use H.245v2 and H.225.0v2 in the same call. >

But can H.225.0 V2 (H.323 V2) and H.245V4 (or 5) be used in the same call???

Gary

------------------------------------------------------ Name : Gary A. Thom Company: Delta Information Systems, Inc. Address: 300 Welsh Rd., Bldg 3 Horsham, PA 19044 USA Phone : +1-215-657-5270 Fax : +1-215-657-5273 E-mail : gthom@delta-info.com ------------------------------------------------------