Thanks for your suggestions.<br>I had already used prefetch for 'receiving files' and 'set_pipelined' for sending files.<br><br>Robey,<br>You are correct HPN patches needs to be applied on both the sides. and I compared<br>
HPN performance using HPN client and HPN server. <br><br>To the surprise FTP takes only 0.4 seconds to transfer a file whereas SFTP takes 25 seconds.<br>I understand the difference between two protocols but it's a huge gap between transfer rates.<br>
<br><br><br><div class="gmail_quote">On Feb 18, 2008 11:35 AM, Robey Pointer <<a href="mailto:robey@lag.net">robey@lag.net</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="Ih2E3d">On 15 Feb 2008, at 6:24, Deepak Rokade wrote:<br><br>> Hi All,<br>> With this mail I want to know "how to improve performance of<br>> paramiko for transferring files over the internet through VPN"<br>
><br><br></div>This sounds really similar to the HPN thread, so you might check the<br>HPN patches.<br><div class="Ih2E3d"><br>> Brief about what we are doing.<br>><br>> I want to transfer files of size 5MB which are compressed with gzip<br>
> format over the VPN. This experiment is being carried out between<br>> two cities located 1000km apart ()<br>><br><br></div>For fast, latent pipes, you'll want large window sizes, but also note<br>that SFTP is *terrible* over high latency links. The folks at the<br>
bazaar project found this out the hard way.<br><br>The problem is that SFTP requires you to send a block of data, then<br>wait for an ack. The stop-and-wait wastes a lot of time if you have<br>long round-trip times.<br><br>
Paramiko can "cheat" a little if you use 'set_pipelined' (for sending<br>files) or 'prefetch' (for receiving files).<br><br>Also note that I think the HPN window improvements require each side<br>
(client & server) to be running with the HPN patches. (Someone correct<br>me if I'm wrong?)<br><font color="#888888"><br>robey<br><br></font></blockquote></div><br><br clear="all"><br>-- <br>Thanx & Regards,<br>
Deepak Rokade<br><br>Do what u Enjoy &<br> Enjoy what u Do...........