TOI Author :: Nanda Kurella

Explicit Congestion Notification (ECN) is an extension to the Internet Protocol and to the Transmission Control Protocol which allows end-to-end notification of network congestion without dropping packets. ECN is an optional feature that is only used when both endpoints support it and are willing to use it. ECN operates over an active queue management algorithm.

This feature allows classification of packets based on the inner CoS value in a double tagged packet.