Mtu & Rwin

[nate]

Thought this would be of interest to some..

After checking Docsdiag yesterday, it confirmed that my 0.5mb increase had been put into effect.
Now, how come I was still only downloading at a max of 110kb/s?!

After some digging around, I found out it was because my RWIN was set very low, restricting me to that speed.
The only thing I can think that set it that low was installing SP2 for XP (first RC1 then RC2).

If you get similar problems, ie. not getting the full speed and know for definite you've been upgraded, check out this page check under the "bandwith" heading.

You'll see something like:
Your RcvWindow limits you to: 20556.8 kbps (2569.6 KBytes/s) @ 200ms

Check its set sufficiently to cope with your upgrade, also it would be worth making sure everything else is in Green, denoting you're ok

[Stuartbe]

The rwin value has nothing to do with your connection speed though it can effect performance. Rwin is the maximum ammount of data that your computer/router will recive before sending an Ack packet.

You can check what your average rwin size should be by using tweak test here - http://www.dslreports.com/tools

HTH

[nate]

OK fair enough it doesn't affect your cable modems speed, I wasn't saying that.

The reason I posted my interpretation of it was because I assumed that this problem would likely affect other XP2 SP2 users, DrTCP doesn't appear to work on SP2, therefor the reg hack would have to be used (details of which can be found using the link given), or find another tool.