Conflicting text in H.323 concerning the requirement for esta blishing a H.245 control channel??

Chris Wayman Purvis cwp at ISDN-COMMS.CO.UK
Tue Mar 20 11:46:30 EST 2001


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 at PHILIPS.COM]
>> Sent: Tuesday, March 20, 2001 4:40 PM
>> To: ITU-SG16 at 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 at isdn-comms.co.uk on 20-03-2001 15:17:14
>> To:     Frank Derks/HVS/BE/PHILIPS at EMEA2
>> cc:     ITU-SG16 at 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 at mailbag.intel.com
>>
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> For help on this mail list, send "HELP ITU-SG16" in a message to
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--
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

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For help on this mail list, send "HELP ITU-SG16" in a message to
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