RTP Payload Format for Global System for Mobile Communications Half Rate (GSM-HR)
RFC 5993
Internet Engineering Task Force (IETF) X. Duan
Request for Comments: 5993 S. Wang
Category: Standards Track China Mobile Communications Corporation
ISSN: 2070-1721 M. Westerlund
K. Hellwig
I. Johansson
Ericsson AB
October 2010
RTP Payload Format for
Global System for Mobile Communications Half Rate (GSM-HR)
Abstract
This document specifies the payload format for packetization of
Global System for Mobile Communications Half Rate (GSM-HR) speech
codec data into the Real-time Transport Protocol (RTP). The payload
format supports transmission of multiple frames per payload and
packet loss robustness methods using redundancy.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5993.
Duan, et al. Standards Track [Page 1]
RFC 5993 RTP Payload Format for GSM-HR October 2010
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. GSM Half Rate . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Payload Format Capabilities . . . . . . . . . . . . . . . . . 4
4.1. Use of Forward Error Correction (FEC) . . . . . . . . . . 4
5. Payload Format . . . . . . . . . . . . . . . . . . . . . . . . 5
5.1. RTP Header Usage . . . . . . . . . . . . . . . . . . . . . 6
5.2. Payload Structure . . . . . . . . . . . . . . . . . . . . 6
5.2.1. Encoding of Speech Frames . . . . . . . . . . . . . . 8
5.2.2. Encoding of Silence Description Frames . . . . . . . . 8
5.3. Implementation Considerations . . . . . . . . . . . . . . 8
5.3.1. Transmission of SID Frames . . . . . . . . . . . . . . 8
5.3.2. Receiving Redundant Frames . . . . . . . . . . . . . . 8
5.3.3. Decoding Validation . . . . . . . . . . . . . . . . . 9
6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.1. 3 Frames . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.2. 3 Frames with Lost Frame in the Middle . . . . . . . . . . 11
7. Payload Format Parameters . . . . . . . . . . . . . . . . . . 11
7.1. Media Type Definition . . . . . . . . . . . . . . . . . . 12
7.2. Mapping to SDP . . . . . . . . . . . . . . . . . . . . . . 13
7.2.1. Offer/Answer Considerations . . . . . . . . . . . . . 14
7.2.2. Declarative SDP Considerations . . . . . . . . . . . . 14
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
9. Congestion Control . . . . . . . . . . . . . . . . . . . . . . 15
10. Security Considerations . . . . . . . . . . . . . . . . . . . 15
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
12.1. Normative References . . . . . . . . . . . . . . . . . . . 16
12.2. Informative References . . . . . . . . . . . . . . . . . . 17
Duan, et al. Standards Track [Page 2]
RFC 5993 RTP Payload Format for GSM-HR October 2010
1. Introduction
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