HEADER COMPRESSION SCHEME

摘要

A method of reducing the bandwidth required to send traffic comprising a payload and a header originating in a first communications network over another communications network, the traffic being characterised by having header information from which a path from its source to destination can be predetermined, the method comprising: determining redundant header information which is not used for forwarding said traffic in said other network; replacing at least part or all of said redundant header information with compression information having a smaller bandwidth than said replaced header information; appending header information to said traffic to enable forwarding along said path in said other network to an egress node; at the egress node, processing the traffic to remove the appended header information and restore the replaced header information by removing the compression information and using the compression information to perform a look-up operation which retrieves the replaced redundant header information from a data store, wherein the same compression information is used to replace the same redundant header information for all said traffic having the same predetermined path; compression information comprising a dummy header data structure which conforms to a communications protocol arranged to be identifiable by traffic type in a carrier frame.