Distributed and monolithic profiles in robust packet header compression

Header compression gains interest with the increasing number of short packets in the Internet, where payload length is small compared to the protocol stack header length. Compression can be applied to the whole protocol stack at once, which is referred to as "monolithic profiles" or can treat individual protocol headers separately, which is referred to as "distributed profiles". In recent ROHC activity, monolithic profiles were preferred due to the domination of RTP/UDP/IPv4 packets in the VoIP area. Considering recent development in the field of transport and network protocols, the distributed profile approach becomes of interest. In this paper, distributed profiles are proposed. Compression efficiency using monolithic and distributed profiles was tested and compared on five TCP/IP, ten RTP/UDP/IP, and five SCTP/IP flows. Monolithic profiles have generally shown somewhat better efficiency, while standalone profiles displayed better robustness when the compressor had to switch to the less efficient operating mode.