similar to: OpenSSH & OpenSSL 1.1

The results, for anyone interested, can be found here http://www.psc.edu/networking/projects/hpn-ssh/results.html Long story short, there doesn't seem to be any notable difference between the two anymore. I still have a few more test combinations to run (<.5ms rtts and against cygwin) so the conclusions might change but, at this point, I'm no longer seeing any sort of performance

The HPN12 patch available from http://www.psc.edu/networking/projects/hpn-ssh addresses performance issues with bulk data transfer over high bandwidth delay paths. By adjusting internal flow control buffers to better fit the outstanding data capacity of the path significant improvements in bulk data throughput performance are achieved. In other words, transfers over the internet are a lot

http://www.psc.edu/networking/projects/hpn-ssh/ Mike Stevens and I just released a new set of high performance networking patches for OpenSSH 3.9p1, 4.0p1, and 4.1p1. These patches will provide the same set of functionality across all 3 revisions. New functionality includes 1) HPN performance even without both sides of the connection being HPN enabled. As long as the bulk data flow is in the

Howdy, As a note, we now have HPN patch for OpenSSH 4.2 at http://www.psc.edu/networking/projects/hpn-ssh/ Its still part of the last set of patches (HPN11) so there aren't any additional changes in the code. It patches, configures, compiles, and passes make tests without a problem. I've not done extensive testing for this version of openssh but I don't foresee any problems. I

Hello, I know that this has been asked before, just wanted to mention that I, too, would like to see the HPN SSH functionality incorporated in the standard OpenSSH. Would there be technical disadvantages integrating the changes? I know we are all pretty busy, but I would certainly spend time to help, e.g. with testing, documentation, etc. Cheers --pwo -- Peter W. Osel - http://pwo.de/ - pwo

Hi, http://www.psc.edu/networking/projects/hpn-ssh/ Clearly, the HPN patches significantly boost throughput performance. This enhancement is entirely from tuning the SSH buffer sizes. Alex Tavcar

Hello, I know this has come up before; but is the HPN patch (or elements thereof) currently being considered for integration in to the OpenSSH code base? Are there pending issues (buffer management, none cipher, etc) which still need to be addressed? We have been using HPN-SSH for over a year now, and like others, have observed significant performance improvement over standard OpenSSH. I can

I hope this is the right list, as I'm desiring a feature addition in openssh. I would like the option to have a 'null' cipher (after the initial authorization, similar to 'delayed' for compression). It would have to be enabled on both client and server and server would never use it unless it was both enabled and asked for by the client. I'd strongly prefer it be able to

We've released a new HPN (High Performance Network) patch for OpenSSH 3.9p1. We've made two major changes - first off we backed out of all the modifications we made to buffer.c. Turns out that it just wasn't necessary once we fixed a nagging bug in channels.c. I also made a minor change to the buffer sizes in the source and sink functions in scp.c Increasing the size of both

If anyone is using the HPN patch on a high performance link I was wondering if you could take a moment to answer a quick question Are you seeing vastly different performance between scp throughput and sftp throughput? On my test network (pittsburgh to chicago) I'm getting 26MB/s with scp (arcfour) and only 6.4MB/s with sftp (arcfour). We just started looking into this but it woudl be nice

Hi, There has been some recent work to improve the speed of the Message Authentication Codes (MACs) that are used in OpenSSH. The first improvement is a change from Markus Friedl to reuse the MAC context, rather than reinitialising it for every packet. This saves two calls to the underlying hash function (e.g. SHA1) for each packet. My tests found that this yielded at 12-16% speedup for bulk

Could someone explain to me how the proxy command regression test works? I'm having a problem as it relates to the HPN patch and could use a little insight into what is happening in the proxy connections. The back story is that the HPN patch was failing the regression tests when it his the proxy connections. It would just hang because the tcp window size that we get when a channel is

I see that 9.6 has been released. Did I miss the announcement and/or the call for testing? I do have an issue with this release in that it breaks interaction with HPN-SSH. The client seems to be window limited to 2MB sending regardless of what is being advertised by the receiver.

We have developed a patch that enables changing the SSH window size using the tcp window size as the source. This allows SSH to obtain maximum use of the bandwidth on high BDP links. We also have a page that describes the changes and performance. http://www.psc.edu/~rapier/hpn-ssh/ The patch against CVS is included here. Common subdirectories: src/usr.bin/ssh/CVS and ssh/CVS diff -u

We see absolutely dismal performance from Canberra to Perth via Aarnet or Grangenet (gig connections across the country). With standard rsync on a tuned tcp stack, we see about 700k/s. I started playing with the --sockopts and have increased the performance to 1.4M/s which is better, but still way off the pace. There are similar patches for ssh at

Hello I have ported OpenSSH 3.8p1 to a LynxOS platform. Recently I heard a report from the field that v2 is perceived to be significantly slower than v1. Is this a known issue? Are there any configuration parameters that can be modified to make v2 faster? Thanks in advance for your response Amba

Hello - Running rsync v3.0.5 on a mixture of CentOS 4.6 and 5.1 systems, using hpnssh as the transport mechanism. I am using rsync to replicate roughly a TB worth of compressed log data per day from a bunch of systems for processing. Every hour the systems generate log files, compress them and then rsync pushes them out to a centralized set of redundant hosts with their storage connected to a

On Fri, 9 Jun 2023, Chris Rapier wrote: > Hi all, > > When a client requests dynamic remote forwarding with -R it delays forking > into the background. In ssh.c we see > > if (options.fork_after_authentication) { > if (options.exit_on_forward_failure && > options.num_remote_forwards > 0) { > debug("deferring postauth fork until

Hi I have small query, all our server are centos based 5 and 5.2 . We are looking ofr a tool to that measure packet loss. we have servers in two IDC's bothin the US and we are trying to download a 2gb file from the internet. Some server are able to download the file at a higher b/w rate in one IDC ...while servers at he the other IDC download the same file at a lowe b/w rate . Is ther any

https://www.psc.edu/networking/projects/hpn-ssh/hpn-v-ssh-tput.jpg "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