[c-nsp] Pix to Pix tunnel performance w/Windows File Sharing,>

[Mikael Abrahamsson]

On Sun, 20 Feb 2005, Hank Nussbacher wrote:

> Playing with MTU/MSS and other tweaks will only take you so far with 
> performance issues for Windows File sharing.  That is why a slew of 
> companies have been formed:

I was about to send an email with the same meaning. Windows filesharing 
(SMB) works like XMODEM but with a ~61kilobyte block size, and does this 
over TCP. REQ block, remote sends block, when the block has been received, 
local REQs another block. During the RTT there (and if TCP NDELAY isn't 
used, even more TCP delay) the line is empty.

Seen with ethereal the TCP SEQ over time graph shows this really well.

SMB was designed for LAN environment and it shows.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se