Signaling Compression (SigComp) Requirements & Assumptions
RFC 3322
Document | Type | RFC - Informational (January 2003; No errata) | |
---|---|---|---|
Author | Hans Hannu | ||
Last updated | 2013-03-02 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 3322 (Informational) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
IESG note | Responsible: RFC Editor | ||
Send notices to | <cabo@tzi.org>, <lars-erik.jonsson@ericsson.com> |
Network Working Group H. Hannu Request for Comments: 3322 Ericsson Category: Informational January 2003 Signaling Compression (SigComp) Requirements & Assumptions Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract The purpose of this document is to outline requirements and motivations for the development of a scheme for compression and decompression of messages from signaling protocols. In wireless environments and especially in cellular systems, e.g., GSM (Global System for Mobile communications) and UMTS (Universal Mobile Telecommunications System), there is a need to maximize the transport efficiency for data over the radio interface. With the introduction of SIP/SDP (Session Initiation Protocol/Session Description Protocol) to cellular devices, compression of the signaling messages should be considered in order to improve both service availability and quality, mainly by reducing the user idle time, e.g., at call setup. Table of Contents 1. Introduction....................................................2 1.1. Protocol Characteristics......................................2 1.2. Cellular System Radio Characteristics.........................3 2. Motivation for Signaling Reduction..............................4 2.1. Estimation of Call Setup Delay Using SIP/SDP..................4 3. Alternatives for Signaling Reduction............................6 4. Assumptions.....................................................7 5. Requirements....................................................8 5.1. General Requirements..........................................8 5.2. Performance Requirements......................................9 6. Security Considerations.........................................11 7. IANA Considerations.............................................11 8. References......................................................11 9. Author's Address................................................12 10. Full Copyright Statement.......................................13 Hannu Informational [Page 1] RFC 3322 SigComp Requirements & Assumptions January 2003 1. Introduction In wireless environments, and especially in cellular systems, such as GSM/GPRS, there is a need to maximize the transport efficiency of data over the radio interface. The radio spectrum is rather expensive and must be carefully used. Therefore, the cellular systems must support a sufficient number of users to make them economically feasible. Thus, there is a limitation in the per user bandwidth. Compressing the headers of the network and transport protocols used for carrying user data is one way to make more efficient use of the scarce radio resources [ROHC]. However, compression of the messages from signaling protocols, such as SIP/SDP, should also be considered to increase the radio resource usage even further. Compression will also improve the service quality by reducing the user idle time at e.g., call setup. When IP is used end-to-end, new applications, such as streaming, will be brought to tiny end-hosts, such as cellular devices. This will introduce additional traffic in cellular systems. Compression of signaling messages, such as RTSP [RTSP], should also be considered to improve both the service availability and quality. New services with their corresponding signaling protocols make it reasonable to consider a scheme that is generic. The scheme should be generic in the meaning that the scheme can efficiently be applied to arbitrary protocols with certain characteristics, such as the ASCII based protocols SIP and RTSP. 1.1. Protocol Characteristics The following application signaling protocols are examples of protocols that are expected to be commonly used in the future. Some of their characteristics are described below. 1.1.1 SIP The Session Initiation Protocol [SIP] is an application layer protocol for establishing, modifying and terminating multimedia sessions or calls. These sessions include Internet multimedia conferences, Internet telephony and similar applications. SIP can be used over either TCP [TCP] or UDP [UDP]. SIP is a text based protocol, using ISO 10646 in UTF-8 encoding. Hannu Informational [Page 2] RFC 3322 SigComp Requirements & Assumptions January 2003 1.1.2 SDP The Session Description Protocol [SDP] is used to advertise multimedia conferences and communicate conference addresses andShow full document text