Subject: RE: libssh2_sftp_write doesn't hang anymore

RE: libssh2_sftp_write doesn't hang anymore

From: Mark Riordan <>
Date: Thu, 11 Nov 2010 20:31:51 -0600

> BTW, that expected throughput, is that what you get when you upload to the

> same server from the same machine using OpenSSH's or putty's sftp?

That is with both psftp and WS_FTP Pro (in SFTP mode).
I get around 6 MB/sec on the very same client and server hardware
for these programs. (FYI, I'm back to using a 100 Mbit/sec Ethernet.
I have a client with a 1 Gbit/sec link, but it's more difficult to get
to and the higher speed isn't yet necessary for our purposes.)

> I checked your 'DebugFast.log' file. It shows:
> Judging from the log, it was a file with "Line 1" to "Line 40000" with
> newlines. That makes it a 468894 byte file.
> I'd say it looks about right.

Right you are - my bad. I have two test files, and one is
4 times the size of the other. This was indeed the 479988-byte one.
Sorry about that. The DebugFast.txt file in that zip shows that the
application thought it sent 479988 bytes.
At any rate, the same principle applies. The NoDebugSlow capture
showing 30517591 uploaded raw bytes is still much larger than would
be necessary for a 479988-byte file.

> If you send an SFTP file using another client, do the inter-packet timings

> look the same?

Well, many of the long delays are when waiting for an ACK, but of
course not all.
I uploaded a zip file with the capture and some supporting files
I used PSFTP for this upload.


Received on 2010-11-12