Bug 224489

Summary: HPN support in openssh
Product: [Fedora] Fedora Reporter: Rimma Ashkinadze <rimma>
Component: opensshAssignee: Tomas Mraz <tmraz>
Status: CLOSED RAWHIDE QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: hugh, jarod, rayvd
Target Milestone: ---Keywords: FutureFeature
Target Release: ---   
Hardware: All   
OS: Linux   
URL: http://www.psc.edu/networking/projects/hpn-ssh/
Whiteboard:
Fixed In Version: openssh-4.7p1-1.fc8 Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-09-07 02:54:42 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Description Rimma Ashkinadze 2007-01-25 16:49:41 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.
Comment 1 Jarod Wilson 2007-07-12 15:40:09 EDT
+1 for adding this, along with seeing if we can help convince upstream to take it...
Comment 2 D. Hugh Redelmeier 2007-07-17 17:08:51 EDT
upstream might be doing something finally.  Not clear. 
https://bugzilla.mindrot.org/show_bug.cgi?id=1337
Comment 3 Tomas Mraz 2007-09-07 02:54:42 EDT
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.