DVB-GSE (Generic Stream Encapsulation) - Robust Header Compression

Introduction

As introduced in TS 102 606-1, the Generic Stream Encapsulation (GSE) protocol is a link layer which provides multiplexing mechanisms that make it possible for several network protocols (for example IP, IPX, Decnet, and Appletalk) to coexist within a multipoint network and to be transported over the same network media. GSE is designed to be deployed across all DVB broadcast bearers which provide a Generic Stream mode.

Due to the use of GSE on broadcast bearers, making efficient use of the available link capacity is an important factor for a cost effective deployment. An additional. special property of broadcast links is the possible presence of non-negligible error rates and long round-trip times. Other existing header compression schemes generally do not perform well when used over links with these properties.

To complement the payload compression offered by some application layer protocols, and enable the use over broadcst links, the present document defines a highly robust and efficient header compression scheme for RTP/UDP/IP (Real-Time Transport Protocol, User Datagram Protocol, Internet Protocol), UDP/IP, and ESP/IP (Encapsulating Security Payload) headers.

While the IETF RFC documents RFC 5795, RFC 3095, RFC 4815, and RFC 3843 define a header compression scheme for unidirectional links, they make no specific provisions for use on broadcast bearers. TS 102 606-2 defines a link layer mechanism to supply the additional information needed for using header compression on DVB broadcast bearers.

Scope

The present document specifies a Robust Header Compression (ROHC) method to be used on DVB streams where the Generic Stream Encapsulation (GSE) TS 102 606-1 protocol is used as the link layer for IP.