[SIPForum-techwg] Comment on section 16.3 (DTMF)

[Spencer Dawkins]

I think the final text you guys are talking about looks roughly like this:

"A SIP-PBX or SP-SSE MUST advertize support for RFC 4733 in its SDP on 
behalf of any Media Endpoint that supports receiving DTMF digits.

"Any Media Endpoint that supports the transport of DTMF tones MUST support 
the negotiation via an SDP offer/answer of the supported method used to 
transport the tones. The Media Endpoint MUST support the ability to use any 
dynamic RTP payload type when negotiating the use of RFC 4733.


"Any Media Endpoint that supports sending DTMF MUST use the RFC 4733 
procedures to transport DTMF tones using the RTP telephone-event payload 
format, provided that the other side has advertized support for receiving 
RFC 4733 in the offer/answer exchange."



Does this work for  people?



Thanks,



Spencer



----- Original Message ----- 
From: "Francois Audet" <audet at nortel.com>
To: "Elwell, John" <john.elwell at siemens-enterprise.com>; 
<techwg at sipforum.org>
Sent: Thursday, April 09, 2009 3:47 PM
Subject: Re: [SIPForum-techwg] Comment on section 16.3 (DTMF)


> Yep.
>
>> -----Original Message-----
>> From: Elwell, John [mailto:john.elwell at siemens-enterprise.com]
>> Sent: Thursday, April 09, 2009 13:22
>> To: Audet, Francois (SC100:3055); techwg at sipforum.org
>> Subject: RE: [SIPForum-techwg] Comment on section 16.3 (DTMF)
>>
>>
>>
>> > -----Original Message-----
>> > From: Francois Audet [mailto:audet at nortel.com]
>> > Sent: 09 April 2009 19:33
>> > To: Elwell, John; techwg at sipforum.org
>> > Subject: RE: [SIPForum-techwg] Comment on section 16.3 (DTMF)
>> >
>> > I think the wording is kind of awkward.
>> >
>> > The real point is that IF you need to either send or
>> receive (or both)
>> > DTMF, it must be done using RFC 4733. Typically, phones for example
>> > don't need to be able to receive DTMF. Some specialized devices may
>> > not have to send them either (e.g., a hot-line phone with
>> no keypad,
>> > etc.).
>> >
>> > What about:
>> >
>> > Any Media Endpoint in the Enterprise network or Service Provider's
>> > network that support receiving DTMF digits MUST advertize
>> its support
>> > for RFC 4733 in it's SDP in an Offer or Answer as appropriate.
>> >
>> > Any Media Endpoint that supports sending DTMF MUST use the RFC 4733
>> > procedures, provided that the other side has advertize support for
>> > receiving RFC 4733 in the Offer/Answer exchange.
>> >
>> > Note that there is no advertizing of the ability to send RFC 4733;
>> > only the ability to receive RFC 4733.
>> [JRE] Fine, but this is not quite in accordance with the
>> architecture, where the SIP-PBX or SP-SSE does the signalling
>> and the media endpoint does the RTP. To correct this I would say:
>>
>> "A SIP-PBX or SP-SSE MUST advertize support for RFC 4733 in
>> it's SDP on behalf of any Media Endpoint that supports
>> receiving DTMF digits.
>>
>> Any Media Endpoint that supports sending DTMF MUST use the
>> RFC 4733 procedures, provided that the other side has
>> advertized support for receiving RFC 4733 in the offer/answer
>> exchange."
>>
>> John
>>
>> >
>> >
>> > > -----Original Message-----
>> > > From: techwg-bounces at sipforum.org
>> > > [mailto:techwg-bounces at sipforum.org] On Behalf Of Elwell, John
>> > > Sent: Thursday, April 09, 2009 06:20
>> > > To: techwg at sipforum.org
>> > > Subject: [SIPForum-techwg] Comment on section 16.3 (DTMF)
>> > >
>> > > 1. "Any Media Endpoint in the Service Provider's network
>> MUST also
>> > > support the ability to transport DTMF tones using the RTP
>> > > telephone-event payload format as described in RFC 4733
>> when using
>> > > any codec.
>> > > Any Media Endpoint in the Enterprise network that
>> originates and/or
>> > > terminates voice traffic MUST support RFC 4733."
>> > >
>> > > Why are requirements slightly different for the two sides.
>> > > Should we combine these statements:
>> > > "Any Media Endpoint in the Enterprise network or Service
>> Provider's
>> > > network MUST also support the ability to transport DTMF
>> tones using
>> > > the RTP telephone-event payload format as described in
>> RFC 4733 when
>> > > using any codec."
>> > >
>> > > 2. Concerning this same text, this doesn't explicitly
>> make provision
>> > > for media endpoints that can transport DTMF but do not need to
>> > > receive it.
>> > > So should we add the sentence:
>> > > "This applies to transmission and, if applicable,
>> reception of DTMF
>> > > tones."?
>> > >
>> > > 3. "Any Media Endpoint in the Enterprise network that
>> supports the
>> > > transport of DTMF tones MUST support the negotiation via an SDP
>> > > offer/answer of the supported method used to transport the tones."
>> > > Shouldn't this apply to SP endpoints too? A text proposal
>> for this
>> > > is in an earlier email dealing with architecture.
>> > >
>> > > John
>> > >
>> > > _______________________________________________
>> > > techwg mailing list
>> > > Send mail to: techwg at sipforum.org
>> > > Unsubscribe or edit options at:
>> > > http://sipforum.org/mailman/listinfo/techwg
>> > >
>> >
>>
>
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