nanog mailing list archives

Re: Best utilizing fat long pipes and large file transfer


From: Glen Turner <gdt () gdt id au>
Date: Mon, 16 Jun 2008 12:18:06 +0930

Robert E. Seastrom wrote:
As a user of hpn-ssh for years, I have to wonder if there is any
reason (aside from the sheer cussedness for which Theo is infamous)
that the window improvements at least from hpn-ssh haven't been
backported into mainline openssh?  I suppose there might be
portability concerns with the multithreaded ciphers, and there's
certainly a good argument for not supporting NONE as a cipher type out
of the box without a recompile, but there's not much excuse for the
fixed size tiny buffers - I mean, it's 2008 already...

Fedora 8 and 9 and Ubuntu 8.04 include the upstream OpenSSH which include
large window patches.  OpenSSH 4.7 ChangeLog contains:

Other changes, new functionality and fixes in this release:
...
 * The SSH channel window size has been increased, and both ssh(1)
   sshd(8) now send window updates more aggressively. These improves
   performance on high-BDP (Bandwidth Delay Product) networks.

Cheers, Glen

--
 Glen Turner


Current thread: