METHOD AND SYSTEM FOR CONGESTION MARKING

The present invention provides a method and system wherein congestion information is taken from a lower level in the protocol stack and used for congestion marking in a higher layer. In particular, the method and system of the invention from a first aspect provide for congestion information in the lower layer to be generated downstream at a congested node, and to be fed back upstream to a source node. The source node then passes the congestion information, or information derived therefrom, up to the corresponding network element responsible for higher layer functions in the protocol stack, where higher level congestion marking can then be performed in dependence on the received lower level congestion information. Thus, congestion information from the lower layer which can typically be generated earlier before significant congestion occurs can be used in higher layer congestion control functions. Preferably the lower layer is the data link layer, and the higher layer is the network layer.