Multiple carrier compression scheme

A method of reducing the bandwidth required to send a plurality of client traffic frames over a plurality of carrier communications networks, each carrier network being arranged to provide a carrier service to said client traffic frames, each client traffic frame comprising client header information and client payload, at least a part of the header information of a frame being usable by a node of a carrier network for forwarding that frame in that carrier network, the method comprising at an ingress node of a second carrier network:

• receiving a frame of client traffic from a first carrier network said frame haying been forwarded in the first carrier network using header information;
• determining first compression information is present in said frame which has replaced original header information not used for forwarding said frames in said first carrier network;
• generating second compression information to replace the header information used for forwarding said frames in said first carrier network;
• replacing the header information used to forward client payloads in said first carrier network with said second compression information;
• and
• appending header information to said client payload to enable forwarding of said received. frame of client traffic in said second carrier network,
• wherein in a data store. accessible to boundary nodes of said second carrier network, said second compression information is stored in association with one or more of the following:
• said replaced header information used for forwarding said frames in said first carrier network;
• said first compression information;
• and
• said original header information replaced by said first compression information.