People using the HPN patch...

Chris Rapier rapier at
Fri Jul 29 23:50:36 EST 2005

Damien Miller wrote:

> Chris Rapier wrote:
>>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 to know that its not just 
>>some weirdness associated with our network.
> Try playing with sftp's -B and -R options, you might be able to get
> better performance on LFPs.

Thanks for the clue. Increasing the number of requests seemed to do the trick. 
Changing the buffer size also had an impact but not as much (100% increase as 
opposed to 400% increase by setting R to 64). Now the big question is, what is 
a request in this context? Are you using them like ACKs to do congestion control?

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