[rfc-dist] RFC 4733 on RTP Payload for DTMF Digits, Telephony Tones, and Telephony Signals

rfc-editor@rfc-editor.org rfc-editor at rfc-editor.org
Mon Dec 18 17:33:28 PST 2006

A new Request for Comments is now available in online RFC libraries.

        RFC 4733

        Title:      RTP Payload for DTMF Digits, 
                    Telephony Tones, and Telephony Signals 
        Author:     H. Schulzrinne, T. Taylor
        Status:     Standards Track
        Date:       December 2006
        Mailbox:    schulzrinne at cs.columbia.edu, 
                    taylor at nortel.com
        Pages:      49
        Characters: 115614
        Obsoletes:  RFC2833

        I-D Tag:    draft-ietf-avt-rfc2833bis-15.txt

        URL:        http://www.rfc-editor.org/rfc/rfc4733.txt

This memo describes how to carry dual-tone multifrequency (DTMF)
signalling, other tone signals, and telephony events in RTP packets.
It obsoletes RFC 2833.

This memo captures and expands upon the basic framework defined in
RFC 2833, but retains only the most basic event codes.  It sets up an
IANA registry to which other event code assignments may be added.
Companion documents add event codes to this registry relating to
modem, fax, text telephony, and channel-associated signalling events.
The remainder of the event codes defined in RFC 2833 are
conditionally reserved in case other documents revive their use.

This document provides a number of
clarifications to the original document.  However, it specifically
differs from RFC 2833 by removing the requirement that all compliant
implementations support the DTMF events.  Instead, compliant
implementations taking part in out-of-band negotiations of media
stream content indicate what events they support.  This memo
adds three new procedures to the RFC 2833 framework: subdivision of
long events into segments, reporting of multiple events in a single
packet, and the concept and reporting of state events.  [STANDARDS TRACK]

This document is a product of the Audio/Video Transport
Working Group of the IETF.

This is now a Proposed Standard Protocol.

STANDARDS TRACK: This document specifies an Internet standards track
protocol for the Internet community,and requests discussion and 
suggestions for improvements.Please refer to the current edition of the 
Internet Official Protocol Standards (STD 1) for the standardization 
state and status of this protocol.  Distribution of this memo is 

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