RE: DTMF timing (was Re: [Sip] INFO ...)

["Michael Procter" <[e-mail]>]

Whilst having the RFC2833 arriving in the timestamped audio stream is certainly beneficial, it is also true to say that the RTP stream generally travels quicker than signalling.  One of the main reasons for this is that the RTP usually travels point-to-point, whilst the signalling path often includes a couple of proxies.  Even if the proxies process the messages in zero time (which they don't), there are still multiple network hops introduced as a consequence.  Additional delays incurred by the proxies/other intermediate signalling elements swiftly add up too.
 
Regards,
 
Michael

________________________________

From: Kevin Attard Compagno [mailto:[e-mail]]
Sent: Thu 01/11/2007 18:00
To: [e-mail]
Subject: RE: DTMF timing (was Re: [Sip] INFO ...)



Apologies for butting in, it's my first post to this list...

My understanding is:

It's not that RFC2833 DTMF delivery arrives quicker that is the point, but that it gets delivered with the rest of the real-time audio inside the RTP stream, timestamped appropriately to insert the tone at the correct point in time within the stream.

---
Kevin Attard Compagno


-----Original Message-----
From: Dean Willis [mailto:[e-mail]]
Sent: 01 November 2007 18:40
To: Elwell, John
Cc: sip List; Paul Kyzivat; Adam Roach
Subject: DTMF timing (was Re: [Sip] INFO ...)


On Nov 1, 2007, at 6:07 AM, Elwell, John wrote:
> [JRE] Performance is a consideration with DTMF, because the speed with
> which the user receives a response from the server can have impact on
> the user experience. RFC 2833 is always likely to get through quicker.

That's an interesting assertion. While I'm inclined to agree that 
your assertion is likely to prove correct, I'm wondering: Does 
anybody out there have real-world measurements on this?

--
Dean


_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [e-mail] for questions on current sip
Use [e-mail] for new developments on the application of sip



_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [e-mail] for questions on current sip
Use [e-mail] for new developments on the application of sip




_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [e-mail] for questions on current sip
Use [e-mail] for new developments on the application of sip