[Jingle] XEP-0181: Jingle DTMF

Diana Cionoiu diana-liste at null.ro
Fri Jul 25 21:30:45 CDT 2008

Hi Rob,

When you do PBX and you use DTMF's to make all kinds of functionalities, 
than you need to have the DTMF's on the signalling path not in the RTP, 
because the RTP goes directly between end points.
This is why SIP people added SIP INFO, so don't even think that you 
don't need DTMF's in signalling.


Robert McQueen wrote:
> Johansson Olle E wrote:
>> I agree that in most situtations, DTMF in the media stream is to be
>> preferred, mostly because
>> of timing issues. In some cases, DTMF is handled out of band for IVR
>> situations, then maybe
>> KPML could be used in the XMPP stream. It's an XML-based definition in
>> RFC 4730.
> What IVR situations can't just process the events out of the RTP stream
> in order to find out what DTMF is being sent? I don't think this is a
> compelling argument for either a) requiring clients to implement two
> DTMF methods, or b) preventing DTMF interoperation between normal Jingle
> and SIP endpoints unless the gateway does extra work.
>> Please also note that 4733 REQUIRES use of SRTP, where RFC 2833 doesn't.
>> That's propably why most SIP devices still only claim support of 4733.
> I think 2833-compliant endpoints can still exchange telephony events
> with 4733-compliant endpoints. It'd be pretty broken if that wasn't the
> case. And it doesn't REQUIRE the use of SRTP, it just says this:
>    To meet the need for protection both of confidentiality and
>    integrity, compliant implementations SHOULD implement the Secure
>    Real-time Transport Protocol (SRTP) [7].
> When we can signal SRTP, we'll probably say the same kind of thing too. :D
>> /Olle
> Regards,
> Rob

More information about the Jingle mailing list