Hi Iljitsch, Perry, I'll admit I haven't been fully following your thread of discussion, I've been a bit busy on some other things (another reason why I like the simple solution - less thinking :-) )
Something to keep in mind for your solution. TCP announces the maximum segment size it can receive in the SYN or SYN/ACK segments, and I'm pretty sure these days that is derived directly from the (current) MTU value of the interface it is going to use at the time of the 3-way handshake. I'm pretty sure that irrespective of if PMTUD (or another local link method) discovers a larger possible PMTU value at a later time during the TCP connection, existing TCP connections will not be able to "burst" up to it. Assuming that you're not planning to modify TCP as well, this means that the knowledge of the "best" possible MTU that TCP can use must be known at the time of the initial 3-way handshake. This limitation possibly applies to other unicast or semi-unicast transport layer protocols too, such as SCTP. Thinking about these solutions another way, all they're really attempting to do is to take the TCP-specific MSS mechanism, generalise it so it can be used for all transport layer unicast connections, and moving the mechanism to the network layer. Regards, Mark. -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
