Charles,
Part of establishing a "point-to-point" call involves opening 2 TCP connnections using the Fast Connect procedure as you described it. If that is the case, then the extract from H.323v2 below is misleading(I believe).
H.323v2: 8.1.7 Fast Connect Procedure
"..... The Fast Connect procedure allows the endpoints to establish a basic point-to-point call with as few as one round-trip message exchange, enabling immediate media stream delivery upon call connection."
I don't see a conflict between that quotation and what I said. You have a basic point-to-point call quickly. Media flow. Then you set up the H.245 session with all reasonable speed WHILE MEDIA ARE FLOWING. So you get your media channels set up as a result of fastConnect, and THEN negotiate other capabilities, master-slave etc.
Oh, and there's no need for a second TCP connection anyway - use H.245 tunnelling.
Regards, Chris
-----Original Message----- From: Chris Wayman Purvis [mailto:cwp@ISDN-COMMS.CO.UK] Sent: Tuesday, March 20, 2001 5:47 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Conflicting text in H.323 concerning the requirement for esta blishing a H.245 control channel??
Charles,
It does NOT defeat ANY of the stated aims of FastConnect. These aims were to get agreed media channels in both directions open as quickly as possible. Doing FastStart AND H.245 gives you your media quickly, and means you have the power of H.245 thereon.
In-band DTMF transfer may be used. If you happen to be using a codec that supports it. If you assume it when you're using an unsuitable codec you'll have a problem. Which is a reason for using H.245 capability negotiation.
Regards, Chris
Agboh, Charles wrote:
which defeats the whole point of having a Fast Connect
procedure (FS +
H.245). Why isn't in-band- DTMF transfer used instead (in FS)?
-Charles
-----Original Message----- From: Frank Derks [mailto:frank.derks@PHILIPS.COM] Sent: Tuesday, March 20, 2001 4:40 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Conflicting text in H.323 concerning the
requirement for
establishing a H.245 control channel??
Chris,
I thought I was being clear enough, so let me try again. 6.2.8/H.323 states that an enpoint must open one (and exactly one) H.245 control channel. When Fast Connect is being used, I assume that the intention is that no such control channel is opened.
To be compliant with 6.2.8/H,323 I would have to open a H.245 control channel irrespective of which type of H.245 procedures I will be using. So if I intend to use Fast Start (and assuming that the other party also supports this), I still have to open a H.245 control channel.
Frank
cwp@isdn-comms.co.uk on 20-03-2001 15:17:14 To: Frank Derks/HVS/BE/PHILIPS@EMEA2 cc: ITU-SG16@mailbag.cps.INTEL.COM@SMTP Subject: Re: Conflicting text in H.323 concerning the requirement for establishing a H.245 control channel?? Classification:
Frank,
Why do you consider this text to be "conflicting"? Specifically, with what does it conflict?
Regards, Chris
6.2.8/H.323 states: "The endpoint shall establish exactly
one H.245
Control Channel for each call that the endpoint is
participating in."
8.1.7/H.323 never states that when Fast Connect is being
used such a
control channel should be established. As far as I understand the mechanism this is only required to switch to "normal" H.245
procedures.
It would seem that section 6.2.8 should be rephrased to
make clear that
the H.245 control channel shall only be established when
"normal" H.245
procedures are being followed and not in the fast connect case.
Frank
-- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001
>> For help on this mail list, send "HELP ITU-SG16" in a message to >> listserv@mailbag.intel.com >> > > >For help on this mail list, send "HELP ITU-SG16" in a message to listserv@mailbag.intel.com
-- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001
For help on this mail list, send "HELP ITU-SG16" in a message to listserv@mailbag.intel.com
-- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv@mailbag.intel.com