On TD26 - Fast TCS and M/S negotiation in H.323v4
rrg at LUCENT.COM
Wed Jun 7 15:58:46 EDT 2000
What I was thinking of was the possibility, under TD-26, that
the called endpoint responded to the initial TCS message in the
H.245 channel before it replied to the fastStart element. If
it could use the early H.245 tunnel, the receiver (originator)
would know the difference and wait for CONNECT or fastStart.
Bob Gilman rrg at lucent.com +1 303 538 3868
Paul Long wrote:
> Bob (Jane?),
> H.323 allows the message that carries the accepted FC channels, e.g.,
> Alerting, to also carry tunneled H.245 messages. What you may be thinking of
> is that 8.2.1/H.323v3 (see below) says that an EP cannot tunnel H.245
> _prior_ to the call-signaling message that carries the accepted FC channels.
> It's okay to do it in the same message, though.
> "The sending of encapsulated H.245 messages or the initiation of the
> separate H.245 connection by either endpoint prior to the sending of a Q.931
> message containing fastStart by the called endpoint terminates the Fast
> Connect procedures."
> Paul Long
> Smith Micro Software, Inc.
> "Primum non nocere"
> -----Original Message-----
> From: Jane Hua [mailto:huajane at YAHOO.COM]
> Sent: Wednesday, June 07, 2000 12:51 AM
> To: ITU-SG16 at MAILBAG.INTEL.COM
> Subject: Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
> The problem is that inclusion of an H.245 message in the tunnel
> FastStart according to section 8.2.1 of H.323. This could be
> by using the early H.245 element for the replys so that FastStart could
> At least this mechanism would make it easy to know that the responder
> called endpoint) was able to overlap FastStart and H.245.
> Bob Gilman rrg at lucent.com +1 303 538 3868
> Paul Long wrote:
> > Bob,
> > H.323 only says that fastStart and h245Control cannot both be included
> > _Setup_, so it could indeed be included in the Setup-UUIE type.
> > Paul Long
> > Smith Micro Software, Inc.
> > -----Original Message-----
> > From: Callaghan, Robert [mailto:Robert.Callaghan at ICN.SIEMENS.COM]
> > Sent: Tuesday, June 06, 2000 10:27 AM
> Hi All,
> As far as my understanding goes, the purpose of prohibiting both
> fastStart and H.245 tunnel in SETUP was to avoid race conditions in two
> tunnels (fastStart can also be considered as a H.245 tunnel with
> different procedures). Here we are adding a new tunnel which will lead
> to more such race scenarios until proper care is taken in defining the
> The decision on this should not be like a voice vote in Congress. The
> procedures should be clearly documented and circulated over the
> reflector and let people argue on those concrete documented steps.
> Let us see, can we fix the problem introduced by introduction of
> Jane Hua
> > To: ITU-SG16 at MAILBAG.INTEL.COM
> > Subject: Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
> > Paul,
> > It would be required in the SETUP, CALL PROCeeding, ALERT, FACILITY,
> > CONNECT message in that all of these messages can be sent before Fast
> > Start
> > is completed or may not be present with Fast Start elements based on
> > Bob
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