Layered Encapsulation of Congestion Notification

Document Type Replaced Internet-Draft (individual)
Author Bob Briscoe 
Last updated 2008-07-14
Replaced by RFC 6040
Stream (None)
Intended RFC status (None)
Expired & archived
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Stream Stream state (No stream defined)
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IESG IESG state Replaced by draft-ietf-tsvwg-ecn-tunnel
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document redefines how the explicit congestion notification (ECN) field of the outer IP header of a tunnel should be constructed. It brings all IP in IP tunnels (v4 or v6) into line with the way IPsec tunnels now construct the ECN field. It includes a thorough analysis of the reasoning for this change and the implications. It also gives guidelines on the encapsulation of IP congestion notification by any outer header, whether encapsulated in an IP tunnel or in a lower layer header. Following these guidelines should help interworking, if the IETF or other standards bodies specify any new encapsulation of congestion notification.


Bob Briscoe (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)