[c-nsp] Bonded T3 Bandwidth issue

[Mikael Abrahamsson]

On Thu, 24 Feb 2011, Stevan Zupanic wrote:

> Keep in mind the Windows TCP scaling limitations, with default window sizes
> an RTT of 10ms gives you a maximum of 52Mbps.

TCP scaling is radically different between Windows versions, you can't 
really call it "Windows TCP scaling limitation". XP is quite different 
from Windows 7.

If you meant XP, please say so. Also XP scales differently depending on 
speed of interface.

<http://msdn.microsoft.com/en-us/library/ms819736.aspx>

If none of the preceding sets the window size, the default receive window 
size is set as follows:

     *

       For a transmission below 1 megabit per second (Mbps), 8 KB.
     *

       For a 1-100 Mbps transmission, 17 KB.
     *

       For a transmission greater than 100 Mbps, 64 KB.

So the speed of the NIC affects the default TCP window size. I guess the 
example you gave was for gig connected machine.

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