Specifying Alternate Semantics for the Explicit Congestion Notification (ECN) Field
There have been a number of proposals for alternate semantics for the ECN field in the IP header [RFC3168]. This document discusses some of the issues in defining alternate semantics for the ECN field, and specifies requirements for a safe co-existence in an Internet that could include routers that do not understand the defined alternate semantics. This document evolved as a result of discussions with the authors of one recent proposal for such alternate semantics.