Date Added: Oct 2009
This paper describes a new protocol using Explicit Congestion Notification (ECN) that protects hosts from the effects of multicast receivers that seek to acquire more than a fair share of network capacity. The technique is described for the IETF Asynchronous Layered Coding (ALC) but also extensible to other transport protocols. It provides a scalable approach that allows a chosen mediating router to determine if downstream receivers have received congestion-free packets. The protocol allows the congestion behaviour of receivers to be policed, based on the reported ECN-nonce values, knowledge of the subscription rules and synchronisation points used by the transport-layer congestion response algorithm.