On Sun, Feb 6, 2011 at 7:20 AM, kellyremo <kellyremo at zoho.com> wrote: > > 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 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!! > They are likely erring on the side of safety. Dynamic buffers could introduce some vulnerabilities. You can generate race conditions in different ways, and whenever there's a dynamic run-time setting this increases the exposure surface. BTW, at the end of the linked article: ms with buffer_append_space in HPN-SSH. If you are experiencing disconnects due to a failure in buffer_append_space please let us know. We're currently tracking some problems with this and we're trying to gather more information to help resolve it. > 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! > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > >
