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

From: Skywing <Skywing@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@es.net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751