We're talking about a lot of things here. I have what I believe is a simple
question:

Is there any combination of TCP implementations (and options) under
discussion here in which the peers WILL NOT interoperate? (i.e. No data
will correctly pass between the hosts).

If the answer is Yes, then I think we have an issue that must be dealt with
in such a way that interoperation happens instead of not.

If the answer is No, then we're arguing over performance optimization of
transition cases, which, while useful, should not bar progress.

To make this absolutely clear - my first requirement is that interoperation
happen. My second requirement is that progress (PMTU, etc) not be impeded,
so long as the first rule is not violated.

	Erik <fair@clock.org>