RTP Payload Format for ITU-T Recommendation G.711.1
RFC 5391
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RFC - Proposed Standard
(November 2008; No errata)
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2015-10-14
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draft-sollaud-avt-rtp-g711wb
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RFC 5391 (Proposed Standard)
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Cullen Jennings
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Network Working Group A. Sollaud
Request for Comments: 5391 France Telecom
Category: Standards Track November 2008
RTP Payload Format for ITU-T Recommendation G.711.1
Status of This Memo
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 unlimited.
Copyright Notice
Copyright (c) 2008 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (http://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Abstract
This document specifies a Real-time Transport Protocol (RTP) payload
format to be used for the ITU Telecommunication Standardization
Sector (ITU-T) G.711.1 audio codec. Two media type registrations are
also included.
Sollaud Standards Track [Page 1]
RFC 5391 RTP Payload Format for G.711.1 November 2008
Table of Contents
1. Introduction ....................................................2
2. Background ......................................................2
3. RTP Header Usage ................................................3
4. Payload Format ..................................................4
4.1. Payload Header .............................................4
4.2. Audio Data .................................................5
5. Payload Format Parameters .......................................6
5.1. PCMA-WB Media Type Registration ............................7
5.2. PCMU-WB Media Type Registration ............................8
5.3. Mapping to SDP Parameters ..................................9
5.3.1. Offer-Answer Model Considerations ...................9
5.3.2. Declarative SDP Considerations .....................11
6. G.711 Interoperability .........................................11
7. Congestion Control .............................................12
8. Security Considerations ........................................12
9. IANA Considerations ............................................12
10. References ....................................................13
10.1. Normative References .....................................13
10.2. Informative References ...................................13
1. Introduction
The ITU Telecommunication Standardization Sector (ITU-T)
Recommendation G.711.1 [ITU-G.711.1] is an embedded wideband
extension of the Recommendation G.711 [ITU-G.711] audio codec. This
document specifies a payload format for packetization of G.711.1
encoded audio signals into the Real-time Transport Protocol (RTP).
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT","RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Background
G.711.1 is a G.711 embedded wideband speech and audio coding
algorithm operating at 64, 80, and 96 kbps. At 64 kbps, G.711.1 is
fully interoperable with G.711. Hence, an efficient deployment in
existing G.711-based Voice over IP (VoIP) infrastructures is
foreseen.
The codec operates on 5-ms frames, and the default sampling rate is
16 kHz. Input and output at 8 kHz are also supported for narrowband
modes.
Sollaud Standards Track [Page 2]
RFC 5391 RTP Payload Format for G.711.1 November 2008
The encoder produces an embedded bitstream structured in three layers
corresponding to three available bit rates: 64, 80, and 96 kbps. The
bitstream can be truncated at the decoder side or by any component of
the communication system to adjust, "on the fly", the bit rate to the
desired value.
The following table gives more details on these layers.
+-------+------------------------+----------+
| Layer | Description | Bit rate |
+-------+------------------------+----------+
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