Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
Dave, I am sure you know that Keypad doesn't allow you to send long tones.
For voice GATEWAYS (like a PBX), it is necessary to perform a full TCS after call setup to know each other's capabilities. A simple example is FAX: for sure a big gateway can not set-up two channels (one for voice and one for fax) just in case, fax tone is detected on one of the ends.
There are other H.245 commands that are necessary in H.245 for PBX functionality: e.g., Third Party pause and re-routing, to offer call features (AVR, hunting, etc.).
All these issues were discussed at length in Osaka. It's déjà-vu all over again...
-----Original Message----- From: Dave Walker [mailto:drwalker@SS8NETWORKS.COM] Sent: Tuesday, June 06, 2000 1:45 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
Paul, why are we even doing this? I'd just tell Bob to use the Keypad Facility IE if he really needs DTMF signalling. You must realize how ridiculous this'll look to advocates of other solutions: the ITU screwed up H.245 tunneling, and now they're adding a new tunnel to fix it - yech.
Dave.
"Paul E. Jones" wrote:
Bob,
For messages other than SETUP, I was assuming we could use
the existing
h245Control field for H.245 message exchange-- only the
SETUP message is a
special case, since it was explicitly disallowed in H.323v2
when fastStart
was also present.
Paul
----- Original Message ----- From: "Callaghan, Robert" Robert.Callaghan@icn.siemens.com To: "'Paul E. Jones'" paulej@PACKETIZER.COM Cc: "'Mailing list for parties associated with ITU-T Study
Group 16'"
ITU-SG16@mailbag.cps.intel.com Sent: Tuesday, June 06, 2000 11:27 AM 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, and
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 v2.
Bob
-----Original Message----- From: Paul E. Jones [mailto:paulej@PACKETIZER.COM] Sent: Saturday, June 03, 2000 6:41 AM To: ITU-SG16@mailbag.cps.intel.com Subject: Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
Paul, Francois, and others,
If we were able to get consensus here, I believe we could
add a field to
the
SETUP-UUIE. I'd rather not put it in the H323-UU-PDU, since it is
intended
for SETUP only as a means of allowing H.245 to used with
fastConnect in a
backward compatible manner.
We have an entire proposal on verbiage to be added to
H.323. I'll have to
review that to see what needs changing-- but there's
actually a lot of
description.
Can we agree to introduce a new "earlyH245" field to go along with "fastStart" in the SETUP?
Paul
----- Original Message ----- From: "Paul Long" Plong@SMITHMICRO.COM To: ITU-SG16@mailbag.cps.intel.com Sent: Friday, June 02, 2000 10:11 PM Subject: Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
Paul,
While not ideal (nothing is), that's a safe, workable
solution. I like
it.
Are you proposing adding the new component to the
H323-UU-PDU or the
Setup-UUIE type? Both locations have their merits. This
then should be
the
new text for section 8.2.1/H.323: "The calling endpoint
shall not
include
both a fastStart element and encapsulated H.245
messages in h245Control
in
the same Setup message. However, the calling endpoint
may include both a
fastStart element and encapsulated H.245 messages in
earlyH245Control in
the
same Setup message." And then explain what the called
endpoint is
supposed
to do when fastStart and earlyH245Control are present.
While we're at
it,
maybe we should define a separate type, i.e.,
H245Control ::= SEQUENCE OF OCTET STRING OPTIONAL -- each
octet string may
contain exactly
-- one H.245 PDUBut now how do the two components, h245Control and
earlyH245Control
otherwise relate to each other, i.e., when fastStart is
not included?
Should
we say that if one is present the other shall not be
present? That would
be
the clearest, IMO. Not much is gained by allowing both.
Remember, the first rule of standards revision is
(everybody repeat
after
me)... "Primum non nocere" ("First do no harm.") - the Roman physician, Galen
Paul Long Smith Micro Software, Inc.
-----Original Message----- From: Paul E. Jones [mailto:paulej@PACKETIZER.COM] Sent: Friday, June 02, 2000 8:14 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: On TD26 - Fast TCS and M/S negotiation in H.323v4
Francois,
I agree that the behavior is desirable, but I still
argue that it will
break backward compatibility. If we can agree with a new field "earlyH245" as a special field for SETUP to do
essentially the same
thing, but only for V4, I would be quite happy-- we get
the same end
result without V3 and V2 compatibility issues.
I do not want to wait until Portland. The Whitepaper
drafts are due
before then and I hope that that meeting will be focused on only critical issues in H.323 and that most of our time will
be spent on
further development of Annexes and perhaps forward
thinking on V5 :-)
Paul
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Francois Audet