Re: Squid's use in proxying satellite users

> Specifically I need to 1) turn off TCP slow start, 2) have TCP not wait
> for acks, and finally 3) a min TCP window size of at least 64Kb.
>

I think you mean "want", not "need". I would be wary of doing this
especially in your case, as you are in an environment where these
features are probably particularly beneficial to the network. You
may find the result of starting with a huge windows is simply that
the sending end gets source quenched quickly and you lose a lot of in
transit packets.

If your connectivity to important sites is good enough, you would
probably be better off trying to maximimise the ability of Squid to
do a proxy connection keep, so that it is running with connections
which are tuned to the real throughput of the network. Even then, a
large idle time might result in an overload when things restart.

Certainly running with huge packet windows to small sites is simply
likely to overload their routers and result in either a fast source
quench or generally annoying them by taking a disproportionate amount
of bandwidth at start up.

As pointed out elsewhere, Acks are a fundamental feature of TCP. I
think that the bit about Nagle was wrong; I think Nagle is to do with
sending packets before they are full.

Disabling slow start creates an illegal TCP implementation, see the
following from RFC 1122, which is also something like STD 2 (internet
standard). MUST means that the implementor has no choice.

        4.2.2.15 Retransmission Timeout: RFC-793 Section 3.7, page 41

           The algorithm suggested in RFC-793 for calculating the
           retransmission timeout is now known to be inadequate; see
           Section 4.2.3.1 below.

           Recent work by Jacobson [TCP:7] on Internet congestion and
           TCP retransmission stability has produced a transmission
           algorithm combining "slow start" with "congestion
           avoidance". A TCP MUST implement this algorithm.

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David Woolley - Office: David Woolley <djw@bts.co.uk>
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