s vermill wrote: > > s vermill wrote: > > > > Group: > > > > On a W2k machine, I've tried several different recommendations > > for adjusting the TCP receive window size. None of them, > > including those directly from Microsoft, seem to have any > > impact. I'm capturing my own traffic and my advertised window > > is always in the 64k range. > > > > I've tried editing the \tcpip\parameters to include > > 'TcpWindowSize' and 'GlobalMaxTcpWindowSize' - neither of > which > > had any effect. I've tried editing \VxD\MSTCP to include > > 'DefaultRcvWindow' - also no effect. > > > > Anyone know how to manipulate the rcv window that my machine > > will advertise. For that matter, what about the other MS > > OSes? XP? Win98? > > > > Thanks all, > > > > Scott > > Well... > > The key TcpWindowSize, when present in the registry under > \tcpip\parameters, does in fact appear to work on W2k and XP > Pro.
Kewl. > I don't know what bad state I got my machine into before, > but it certainly wasn't taking effect earlier. In any case, > the value can be entered in decimal or hex and is in bytes. > The key GlobalMaxTcpWindowSize does not appear to work on > either W2k or XP Pro under \tcpip\parameters. It perhaps > should be entered elsewhere, but that's where MS said to put it. > > An interesting side note: Ethereal apparently doesn't support > window scaling. I use a download test site that will tell you > your rcv window if it remains consistent enough throughout the > test. It follows exactly what I enter into the registry, > whether above or below 65535. However, when using a value > above 65535 (such as 93360), Ethereal reports it only as > 65535. This may have been why I was only "seeing" a range of > 64420 - 65535 earlier. This further confused the situation. > Serves me right for using an open-source PA, but the price is > right. I recently heard of another free analyzer. I don't know if it reports the window size correctly when scaling is used, but it might. http://analyzer.polito.it/ I'm partial to EtherPeek from WildPackets (as you know! ;-). It does report the window correctly when scaling is used, but, alas, it's not free. > > Thanks all for your insightful feedback. You were a great > help. And I was able to do what I originally set out to - > seriously restrict my download rates by manipulating this > value. I'm hopeful it will go a long way towards demonstrating > a very technical issue to somewhat non-technical people. It's > something tangible for them to wrap their minds around sitting > right in front of a desktop machine. That's great. Sounds like a good learning tool in many ways. Priscilla > > Regards all, > > Scott > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=59430&t=59400 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
