H.323 Annex E optional?
Paul E. Jones
paul.jones at ties.itu.int
Thu Jul 29 23:58:59 EDT 1999
The endpoint does not indicate a preference-- it is to indicate capability.
The gatekeeper may force an endpoint to use Annex E by setting the flag in
----- 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 RRQ
> (and a GK, in an LCF) whether it supports H.323 Annex E (call-signaling
> an unreliable channel), so Annex E is apparently optional. For example,
> 7.9.1/H.225.0v3: "supportsAnnexECallSignalling - If TRUE, this indicates
> that the sender of this message is capable of call signalling [sic] on an
> 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 to
> 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 the
> 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 support
> this Annex?
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