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. 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. 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. Regards all, Scott Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=59428&t=59400 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
