OpenSSH GSoC Project

[Salvador Fandino]

----- Original Message ----
> From: Damien Miller <djm at mindrot.org>
> To: Salvador Fandino <sfandino at yahoo.com>
> Cc: Ben Lindstrom <mouring at eviladmin.org>; openssh-unix-dev at mindrot.org
> Sent: Wednesday, March 25, 2009 1:18:54 PM
> Subject: Re: OpenSSH GSoC Project
> 
> Why bother? With the current packet size the overhead is something like
> 30KB per GB of data transferred, but increasing this makes the protocol
> perform worse for multiple concurrent operations (which we admittedly 
> underutilise now) and less responsive to early aborts, etc.

The problem is not overhead but latency, at least in theory.

With current configuration, we have 32KB packet-length * 64
max-packets-queued = 2MB of data on the "air", so for instance, if the
communication line supports 4MB/s, but the roundtrip is 1 second, only
50% of the bandwidth will be used (AFAIK, the underlaying SSH transport
does not use any ACK mechanism internally and so is not affected by
round-trip, and TCP can handle that delays also).

I suppose those would be rare cases in practice, so probably, it doesn't worth the trouble... 

- Salva