Skip to main content

RTP Payload Format for mU-law EMbedded Codec for Low-delay IP Communication (UEMCLIP) Speech Codec
RFC 5686

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: Internet Architecture Board <>,
    RFC Editor <>, 
    avt mailing list <>, 
    avt chair <>
Subject: Protocol Action: 'RTP payload format for mU-law EMbedded Codec for Low-delay IP communication (UEMCLIP) speech codec' to Proposed Standard

The IESG has approved the following document:

- 'RTP payload format for mU-law EMbedded Codec for Low-delay IP 
   communication (UEMCLIP) speech codec '
   <draft-ietf-avt-rtp-uemclip-06.txt> as a Proposed Standard

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

The IESG contact persons are Cullen Jennings and Robert Sparks.

A URL of this Internet-Draft is:

Ballot Text

Technical Summary

This document describes the RTP payload format of a mU-law Embedded
Coder for Low-delay IP communication (UEMCLIP), an enhanced speech codec
of ITU-T G.711.  The bitstream has a scalable structure with an embedded
u-law bitstream, also known as PCMU, thus providing a handy  transcoding
operation between narrowband and wideband speech.

          Working Group Summary

This is a reasonably standard RTP payload format. The document has been
reviewed by the AVT working group and all open issues were addressed 

          Document Quality

Media type review was conducted starting 26 February 2008, with no 
objections raised. There is at least one implementation. 


Roni Even is the document shepherd. 

The responsible area director is Cullen Jennings.

RFC Editor Note

   Followings are additional guidelines for establishing a session using
   an offer-answer model.

   The following is a detailed list on the semantics of using
   the UEMCLIP payload format in an offer-answer exchange:

In S1, second paragraph:
    switched using SDP exchange.
   changed using an SDP exchange.

In S2, first paragraph:
   shift to the wideband.
  shift to using wideband communication.

RFC Editor Note