RFC 3096 (rfc3096) - Page 2 of 8

Requirements for robust IP/UDP/RTP header compression

RFC 3096            Requirements for IP/UDP/RTP ROHC           July 2001


   (specified by the 3GPP standards organization).  It is critical for
   these standardization efforts that a suitable header compression
   scheme is developed before completion of the Release 2000 standards.
   Therefore, it is imperative that the ROHC WG keeps its schedule.

2.1 Impact on Internet infrastructure

   1. Transparency: When a header is compressed and then decompressed,
   the resulting header must be semantically identical to the original
   header.  If this cannot be achieved, the packet containing the
   erroneous header must be discarded.

   Justification: The header compression process must not produce
   headers that might cause problems for any current or future part of
   the Internet infrastructure.

   2. Ubiquity: Must not require modifications to existing IP (v4 or
   v6), UDP, or RTP implementations.

   Justification: Ease of deployment.

   Note: The ROHC WG may recommend changes that would increase the
   compression efficiency for the RTP streams emitted by
   implementations.  However, ROHC cannot rely on such recommendations
   being followed.

2.2 Supported headers and kinds of RTP streams

   1. IPv4 and IPv6: Must support both IPv4 and IPv6.

   Justification: IPv4 and IPv6 will both be around during the
   foreseeable future.

   2. Mobile IP: The kinds of headers used by Mobile IP{v4,v6} should be
   compressed efficiently.  For IPv4 these include headers of tunneled
   packets.  For IPv6 these include headers containing the Routing
   Header, the Binding Update Destination Option, and the Home Address
   option.

   Justification: It is very likely that Mobile IP will be used by
   cellular devices.

   3. Genericity: Must support compression of headers of arbitrary RTP
   streams.







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