Relationship of H.323 and H.245 versions

Paul Long Plong at SMITHMICRO.COM
Thu Jan 21 17:20:50 EST 1999

                From:   Jim Toga [SMTP:jim.toga at INTEL.COM]
                This is getting close.   One potential problem surrounds
                (for example GKs in a GK-routed call).  We need to indicate
what exactly is
                the expected behaviour of 'M' entities when they get 'N' type
                (that look like 'M' messages with extentions.)

                I would contend that the reality of the situation is that all
we can
                stipulate, is that the 'M' entities don't crash in the
presense of 'N'
                messages.  We can't mandate that 'M's  pass new
                (uninterpreted/not-understood) data on.  Obviously if there is
an existing
                opaque field defined, this _shall_ be forwarded.


I thought I addressed this in the last sentence, "In addition, if a >product
is relaying an ASN.1 value, it shall encode the same value that it >decoded,
regardless of its own version or the version of the value's sender." This is
for intermediate entities such as gatekeepers that relay, or route, call
signaling and control messages between entities. My company is not in the
gatekeeper business, so with my lack of familiarity I could be off base here,
but I believe this statement is necessary to mitigate the earlier statement,
"Each product shall _encode_ and decode the H.245 and H.225.0 ASN.1 syntax
trees defined in their respective version of H.323." The last sentence
sanctions, for example, a v1 gatekeeper relaying v2 messages. I assume this is
a requirement and that we can indeed mandate it.

Was I not clear, or did I simply not address your concern?

Paul Long
Smith Micro Software, Inc.

More information about the sg16-avd mailing list