OpenSSH could be faster...then why don't they path it??

kellyremo kellyremo at
Sun Feb 6 12:20:44 UTC 2011

"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."

My question is: So Why Does the original OpenSSH has "limited statically defined internal flow control buffers"?? It could be way faster, even 10x!!

With the HPN-SCP path it could be the descendant of FTP! Why aren't there any ""OpenSCP packages""? ('normal SCP+HPN-SCP path+no local user needed for SCP'ing+chroot by default')

Any opinions?

Thank you!

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