[e2e] Question on ssthresh setting in RFC 2581

[Tim Dorcey]

> However: It´s the purpose of CWND to estimate the path´s capcaity in
> oder to provide propoer _congestion_ control.

I think the issue is that CWND becomes stale if the sender enters a period
where it is not filling the CWND (because the application is not providing
enough data).  Suppose, CWND were to grow large during a period of heavy
transmission, and then the application slows to sending only a single
segment per round trip.  If a loss then occurs, the implication is that the
network may be too congested to send more than a single segment per round
trip.  FlightSize better measures the actual load being placed on the
network at the time a loss occurs.

Tim