Red Hat Bugzilla – Bug 224489
HPN support in openssh
Last modified: 2007-11-30 17:11:54 EST
Description of problem:
No HPN (High Performance Networking) support in distributed version of openssh.
from Abstract on http://www.psc.edu/networking/projects/hpn-ssh/ :
SCP and the underlying SSH2 protocol implementation in OpenSSH is network performance limited by
statically defined internal flow control buffers. These buffers often end up acting as a bottleneck for
network throughput of SCP, especially on long and high bandwith network links. Modifying the ssh
code to allow the buffers to be defined at run time eliminates this bottleneck. We have created a patch
that will remove the bottlenecks in OpenSSH and is fully interoperable with other servers and clients. In
addition HPN clients will be able to download faster from non HPN servers, and HPN servers will be able
to receive uploads faster from non HPN clients. However, the host receiving the data must have a
properly tuned TCP/IP stack.
This patch is important for performance on high bandwidth networks.
+1 for adding this, along with seeing if we can help convince upstream to take it...
upstream might be doing something finally. Not clear.
Please test openssh-4.7p1-1.fc8 as soon as it is released (after F8T2 release).
It doesn't contain the full HPN patch, but there are some high-latency
high-bandwith network improvements.