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SubjectRe: TCP timer bug in 2.0.x
> So, a few questions for you. First, what is the latest 2.0.x kernel
> you tried this with? There was a problem prior to 2.0.30 that would
> have caused the behavior you observe specifically in the case of
> a route drop.

I first saw it on 2.0.29. I don't recall now whether I checked it on
an unpatched 2.0.30; I'll have to recompile and test it further.

> Two notes on this. The 2.0.x TCP goes into slow start when doing
> retransmissions. This is probably a mistake on reflection. Packets
> should only be send one for every ACK received during retransmission.
> Second, if your path is lossy it can be very hard to get out of
> retranmission mode. What tends to happen is that every packet you send
> just after a retransmission also gets lost, and then has to be retransmitted.
> In this way you never get a good time sample, and never get to reset your
> RTO timer. The slow start behavior I mention above probably agravates this.

The patch that I posted essentially disables this slow-start.

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