Re: bandwidth for bkbits.net (good news)

Andrea Arcangeli
2003-09-01T16:38:24Z

On Mon, Sep 01, 2003 at 05:28:31PM +0100, Alan Cox wrote:
> On Llu, 2003-09-01 at 17:13, Andrea Arcangeli wrote:
> > > Each ACK that has caused previous delays generally opens up a 64K window
> > > so you get bursts of data incoming. A sequence of acks can cause the
> >
> > the congestion avoidance shouldn't allow what you say. It sends a few
> > packets immediatly (cwnd starts > 1 recently), and that's why
> > non-keepalive connections are bad, but after that the congestion window
> > will remain low if we drop the packets.
>
> You may trigger fast retransmit patterns. Thats why you have to bend the
> window.

fast restransmit are good to trigger, they don't arrive in a flood like
if we had a huge cwnd, if we can send packets out of the network,
they're right to be sent. During congestions the outgoing acks will be
rejected too (it's limiting both ways).

there is no difference between artificial congestion generated by a
shaper and a true congestion. If tcp is correct it has to slowdown
immediatly when it notices congestion.

I also don't see anything specific to a busy http server non support
keepalive in this ack-fast-retransmit matter.

Andrea