Showing results for 
Search instead for 
Did you mean: 

ADSL Modem MTU Settings


ADSL Modem MTU Settings

Hi All,

I am a newbie and have a quick question with regards to MTU settings.

I have a 3Com ADSL Modem ( Model: 3CRWE754G72-A ) and at present the MTU setting in the Modem settings themselves - not in WinXP- are set to 1478. Can anyone at Plusnet or otherwise tell me what the optimum/preffered MTU rate for ADSL modems is at PlusNet?

Thanks in advance.

A. Smiley
Posts: 45
Registered: 05-04-2007

ADSL Modem MTU Settings


Have a look at

Lots of info here that may help you.

Community Veteran
Posts: 14,469
Registered: 30-07-2007

ADSL Modem MTU Settings

The best MTU setting varioes from system to system so no one figure is the best. You will have to experiment with some figures to see which suits your system config the best.

The MTU setting in windows should match that of your modem/router and also look at the windows RWIN setting as that can have a big impact on speeds as well.

See MTU tweak for more info and some suggested figures.

ADSL Modem MTU Settings (read other peoples experiences/probs) (how to change MTU/RWIN in win XP) (how to check your setup)

Check out their FAQ's

This is where I learnt all about MTU and RWIN

After many hours reading & playing about I ended up with:

MTU 1472
RWIN 40096 (2Mb settings)

As stated above everyones setup is different.

I hope this helps, If someone had pointed me to these sites, it would have saved me hours of reading and stopped me ask some very dumb Q's in and around here! :lol: :roll:


p.s. please ignore the "2+ sec stall" thing. It's been doing that ever since PN installed those god-damned packet sniffers!