Re: Betr.: FW: [AVT] Missing events in RFC 2833

Based on this intervention, I would propose to add the list of events 
given by Gunnar to those already given in RFC 2833.

Paul E. Jones wrote:

> Tom,
> 
> I don't think we can say that North American GWs only speak Baudot.  We must
> allow a V.21 user to call home to England, for example.  Your point about
> the use of RFC 2833 for start-up messages is valid and is likely to occur
> between two gateways, as they would have negotiated the use of certain RFC
> 2833 tones and event messages.  Such description falls into the scope of
> ITU-T V.ToIP.
> 
> However, if a gateway happened to terminate to a Pocket PC, for example, no
> such tones would be negotiated or used.  The gateway could either "eat"
> those tones or assume it's a textphone device.  The behavior needs to be
> specified somewhere... perhaps also in V.ToIP?
> 
> In any case, I think we're in agreement that RFC 2833 should not be used as
> a text transport mechanism.  It might be used as part of start-up exchanges
> before it can be determined that the calling/called device is a modem, fax,
> or TTY device.  GW-GW calls have slightly special requirements that IP
> phones do not have.
> 
> Paul
> 
> ----- Original Message ----- 
> From: "Tom Taylor" <taylor@nortelnetworks.com>
> To: "Arnoud van Wijk" <a.vwijk@viataal.nl>
> Cc: "'Paul E. Jones'" <paulej@packetizer.com>; <avt@ietf.org>;
> <gunnar.hellstrom@omnitor.se>; <toip@snowshore.com>; <gv@trace.wisc.edu>
> Sent: Wednesday, December 03, 2003 1:19 PM
> Subject: Re: Betr.: FW: [AVT] Missing events in RFC 2833
> 
> 
> 
>>OK, so in North America the gateway always emulates a Baudot terminal.
>>That means it won't be possible to negotiate alternating text and voice
>>with a V.18 terminal.  I imagine Gunnar's bitter response to that one is
>>that nobody is making V.18 terminals anyway.
>>
>>Arnoud van Wijk wrote:
>>
>>
>>>I think the question we need answered is:
>>>" Do we need to transport real-timing streaming text (aka Interactive
> 
> Text)
> 
>>>through PSTNs with RFC 2833 (a beefed up version of it)?"
>>>
>>>For Interactive Texting, gateways it will be necessary to allow backward
>>>compatibility with analogue textphones. Transcoding from T.140/RTP into
> 
> the
> 
>>>local legacy textphone protocol. For America it is then Boudot.
>>>All that the gateway has to do is simply connect to a PSTN using Boudot
> 
> over
> 
>>>the voice channel. Every PSTN connects with an Interactive Text gateway.
> 
> And
> 
>>>that IT gateway does the transcoding, so that the PSTN sees it as a
> 
> voice
> 
>>>channel as it is done today.
>>>
>>>There is then no RFC 2833 involved for the Interactive Texting.
>>>
>>>Thus when we get 2 PSTN's that are linked together over IP for a voice
> 
> call,
> 
>>>then is it much easier to send the text as RFC 2793.
>>>So, the only requirement is then that every PSTN must have a means to
>>>transcode RFC 2793 into local analogue text telephony (directly or via
> 
> an IT
> 
>>>gateway).
>>>
>>>I want to have clarity on this before starting to complicate matters
> 
> even
> 
>>>more. Analogue text telephony is a dying beast. And my goal is to kill
> 
> it as
> 
>>>fast as possible without any problems.
>>>
>>>Greetz
>>>
>>>Arnoud
>>>
>>>Drs. Arnoud A. T. van Wijk
>>>Viataal
>>>Research & Development
>>>Afdeling RDS
>>>Theerestraat 42
>>>5271 GD Sint-Michielsgestel
>>>The Netherlands.
>>>Mobile: +31651921948
>>>International text telephone: +31735588408
>>
>>
>>
>>_______________________________________________
>>Audio/Video Transport Working Group
>>avt@ietf.org
>>https://www1.ietf.org/mailman/listinfo/avt
>>
> 
> 
> 

_______________________________________________
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