H.323 Annex E optional?
Paul E. Jones
paul.jones at ties.itu.int
Fri Jul 30 13:46:30 EDT 1999
That does seem a bit misleading, but it was not the intention. The
intention was for the endpoint to indicate support and, based on that
indication, the gatekeeper could mandate usage of Annex E. By no means
did we intend for a gatekeeper for attempt to force an endpoint to
use Annex E when it does not support it.
On Fri, 30 Jul 1999, Paul Long wrote:
> Okay, but what if the EP does not indicate that it has this capability?
> 7.9.2/H.225.0v3 currently says that the EP _shall_ use an unreliable channel
> if in receipt of an RCF with useAnnexECallSignalling set to TRUE. Period.
> Regardless of whether the endpoint indicated the capability in its RRQ. The
> following would eliminate the ambiguity and possible misunderstanding:
> 7.9.2/H.225.0v3: "useAnnexECallSignalling - If TRUE and
> supportsAnnexECallSignalling was set to TRUE in the RRQ to which this
> message is in response, the endpoint receiving this message shall use call
> signaling exclusively on an unreliable transport channel as described in
> H.323 Annex E when placing calls."
> Paul Long
> Smith Micro Software, Inc.
> -----Original Message-----
> From: Paul E. Jones
> To: ITU-SG16 at MAILBAG.INTEL.COM
> Sent: 7/29/99 8:58 PM
> Subject: Re: H.323 Annex E optional?
> The endpoint does not indicate a preference-- it is to indicate
> The gatekeeper may force an endpoint to use Annex E by setting the flag
> the RCF.
> ----- Original Message -----
> From: Paul Long <Plong at SMITHMICRO.COM>
> To: <ITU-SG16 at mailbag.cps.intel.com>
> Sent: Tuesday, July 27, 1999 7:53 PM
> Subject: H.323 Annex E optional?
> > Is H.323 Annex E optional? H.225.0 says that an EP can indicate in an
> > (and a GK, in an LCF) whether it supports H.323 Annex E
> > an unreliable channel), so Annex E is apparently optional. For
> > 7.9.1/H.225.0v3: "supportsAnnexECallSignalling - If TRUE, this
> > that the sender of this message is capable of call signalling [sic] on
> > unreliable transport channel as described in H.323 Annex E."
> > However, H.225.0 also says that via an RCF or ACF a GK can force an EP
> > use Annex E. For example,
> > 7.9.2/H.225.0v3: "useAnnexECallSignalling - If TRUE, this parameter
> > indicates that the endpoint receiving this message shal [sic] use call
> > signalling [sic] exclusively on an unreliable transport channel as
> > in H.323 Annex E when placing calls."
> > There is nothing in the Recommendations that requires a GK to abide by
> > EP's capabilities. Is this an oversight, or does the EP merely
> indicate in
> > its RRQ a preference for supporting Annex E, and it must therefore
> > this Annex?
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