Important New Requirement for IPv4 Requests

Sat Apr 25 02:16:18 UTC 2009

Keep in mind that you also need to patch your clients for perf improvements bidirectionally.  As well as patching locally means you must assume responsibility for custom builds for security fixes on all of your clients and servers.

- S

-----Original Message-----
From: Kevin Oberman <oberman at es.net>
Sent: Friday, April 24, 2009 13:39
To: Skywing <Skywing at valhallalegends.com>
Cc: Jo Rhett <jrhett at netconsonance.com>; Joe Greco <jgreco at ns.sol.net>; bmanning at vacation.karoshi.com <bmanning at vacation.karoshi.com>; nanog at nanog.org <nanog at nanog.org>
Subject: Re: Important New Requirement for IPv4 Requests

> From: Skywing <Skywing at valhallalegends.com>
> Date: Fri, 24 Apr 2009 10:55:07 -0500
>
> Of course, sftp and other ssh-based protocols are *still* hamstrung to
> a maximum of 32k data outstanding due to hardcoded SSH channel window
> sizes by default for most people, unless you're patching up both your
> clients and servers.
>
> Sadly, this blows ssh out of the water for anything with even modest
> high-bitrate requirements over moderate-BDP links.

The HPN patches for OpenSSH are readily available and, at least on
FreeBSD, including them is just a single checkbox when you install.

That said, I have been told that there is a corner case where a transfer
using the HPN patches will lock up. I have never seen it, but that is
purported to be the reason that OpenBSD has not accepted the patches
for the base OpenSSH software.
--
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net                  Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751