H.323 (8.1) Phase A - Call Setup

Bob Gilman rrg at AVAYA.COM
Fri Jul 20 19:55:22 EDT 2001


Paul-
Based on your argument (with which I agree), we should include the
Progress message in the list, along with Alerting.  That assures
some feedback to the user within the 4 seconds.
-Bob
----------------------------------------------------
Bob Gilman       rrg at avaya.com      +1 303 538 3868


"Paul E. Jones" wrote:
>
> Peter,
>
> Alerting was the intent.  Call Proceeding not produce a ringing sound in the
> caller's ear.  H.323 devices have to be able to send an Alerting, though
> they're not required to do so if they can send a Connect within 4 second.
> The 4 seconds is the T303 timeout and the T303 timer is disabled when
> receiving Alerting, too... not just Call Proceeding.
>
> The ideas are related, but independent.  What we have seen some folks do is
> send a Call Proceeding to the caller and then nothing else until the
> connect.  The result is that the calling party hears silence for a very long
> time: that's not good.
>
> Paul
>
> ----- Original Message -----
> From: "Peter Price" <PeterP at VEGASTREAM.COM>
> To: <ITU-SG16 at mailbag.cps.INTEL.COM>
> Sent: Friday, July 20, 2001 6:54 AM
> Subject: H.323 (8.1) Phase A - Call Setup
>
> > Hi folks,
> >
> > I think I may have found some incorrect text in H.323 8.1
> >
> > The same text appears in both V3 and V4 so I suspect nobody has commented
> > before.
> >
> > In the paragraph beginning:
> > "An endpoint shall be capable of sending the Alerting message. ..."
> >
> > it goes on to say:
> > "If an endpoint can respond to a Setup message with a Connect, Call
> > Proceeding, or Release Complete within 4 seconds, it is not required to
> send
> > the Alerting message. An endpoint sending the Setup message can expect to
> > receive either an Alerting, Connect, Call Proceeding, or Release Complete
> > message within 4 seconds after successful transmission."
> >
> > I believe the first sentence here should really be discussing the
> > requirement to send a Call Proceeding (not Alerting) message.
> > The period of 4 seconds in the last sentence is related to T303 which is
> > specifically terminated by a Call Proceeding message in order to extend
> the
> > timeout for the sending endpoint.
> >
> > I think the sentence should read:
> > "If an endpoint can respond to a Setup message with a Connect, Alerting,
> or
> > Release Complete within 4 seconds, it is not required to send the Call
> > Proceeding message."
> >
> > This is then consistent with the use of Call Proceeding described in
> 8.1.8.2
> > (second para).
> >
> > Peter Price
> >
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> >
>
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