1. Your ISP, their caps and type of connection.
2. Your maximum anticipated latency.
3. RWIN that you found with the formula.
4. Did your speed improve?
Here is what I want you to do to fing your perfect RWIN.
1. Find your maximum anticipated latency, to do so download one of the following files from these FTP servers:
ftp://ftp.newaol.com/aol6.0/179902/setupaol60.exe
ftp://ftp1.optonline.net/pub/test64
While the file is downloading you need to run a tracert to a few websites of your choice. Write down the highest number you get with every tracert. Do this test about 5 times and drop the highest latency you get and the lowest latency you get and average the other 3. This number will be your maximum anticipated latency. Now use the following formula to find your optimum RWIN.
To calculate RWIN use the following:
(Maxium Bandwidth * Maxium Anticipated Latency) / 8
Example of my results with a 3000 download cap with an Anticipated Latency of 100 ms:
(3000 x 100) / 8 = 37500 To make it a multipule of MSS divide by 1460:
37500 / 1460 = 25.68 Then round to the nearest even whole number:
26 x 1460 = 37960 is my "perfect" RWIN
I was suprised at the results and I can honestly say that my speed is faster than ever.
Now for the testing to see if there is any improvement, do multiple (5 tests or more clearing your temporary internet files after each test) from Speakeasy's servers here http://speakeasy.net/main.php?page=sup_pops the reason I suggest using Speakeasy is because it's the same test everywhere. I want you to test at different locations across the US, not just the closest server to you and record the results.
It has always been suggested to test at the server closest to you, but that is really an inaccurate way to test since we all surf the internet all over the world and download files from servers everywhere including file sharing apps. It can't be as accurate if the test is very close to you and doesn't have many hops (servers) to go through to get to you.
You can use the TCPOptimizer or CableNut to put in your RWIN, just remember that with the TCPOptimizer the value goes in the box TCP ReceiveWindow and CableNut for 2K & XP it will go in GlobalMaxTcpWindowSize & TcpWindowSize and 98 & ME it will go in DefaultRcvWindow & GlobalMaxTcpWindoSize.
What I have found out so far is this:
I tested the following RWINs on my connection:
17520, 32120, 64240, 128480, 256960, 513920
Here is what I found:
17520 - slowest overall
32120-64240 - fastest and most stable overall
128480-256960 - fast on close servers but much slower on distant servers
513920 - slowest overall with all tests
What I am finding is that a very large RWIN is good for geographically close servers that have very few servers to pass through to get to which would be a much less chance for dropped packets and retransmitted packets, but on distant tests the larger values were the worst since there were multiple servers to pass through and thereby greatly increased the chance for dropped packets and retransmissions thereby noticeably decreased my bandwidth.
The moderate values were by far the best overall due the the fact that they decreased the chances for dropped packets and retransmissions. As I showed above the value that I found to work the best for me using the formual above was 37960 and I can honestly say my conneciton has never been faster.
If you have any questions about what to do please PM me or just add to this thread and please post your results. Maybe we can all have faster connections if this is followed?
P.S. This is not intended to prove anyone wrong or right, it's to help everyone get the most from their connections.
anyone else wanna help?
