The PCN Piggybacking Edge Behaviour
Huawei Technologies
Precongestion notification (PCN) is a means for protecting quality of service for inelastic traffic admitted to a Diffserv domain. The overall PCN architecture is described in RFC 5559. This memo describes a behaviour for PCN egress nodes known as the "piggybacking" edge behaviour, because it "piggybacks" PCN information in resource signalling messages. This version of the memo describes two alternatives, where piggybacking is derived from the CL edge behaviour and where it is derived from the SM edge behaviour. The SM and CL edge behaviours are specified in companion documents.