Re: [pmtud] Re: [dccp] PMTU issues

[Eddie Kohler <kohler@icir.org>]

>   A packetization layer should set an ECN codepoint in
>   the packets it sends IFF it is also doing Packetization
>   Layer Path MTU Discovery (PLPMTUD) and is not
>   expecting to get ICMP's back from the network in
>   response to too-large packets being dropped.

Why overload the ECN bit this way?  ECN should be used to indicate
end-to-end congestion control compliance.  In fact RFC 3168 requires that:
"... the transport protocol must be capable of reacting appropriately to
the receipt of CE packets." THat's independent of MTU discovery, or at
least should be pointed out.

Eddie