Accurate ECN Feedback in TCP
Mirja Kühlewind, Richard Scheffenegger · 2011
Explicit Congestion Notification (ECN) is an IP/TCP mechanism where network nodes can mark IP packets instead of dropping them to indicate congestion to the end-points. An ECN-capable receiver will feedback this information to the sender. ECN is specified for TCP in such a way that only one feedback signal can be transmitted per Round-Trip Time (RTT). Recently new TCP mechanisms like ConEx or DCTCP need more accurate feedback information in the case where more than one marking is received in one RTT.