changing RWIN settings

[Supanova]

Hmm iv just been on the speedguide.net website to try and squeeze some extra speed out of my IDnet connection, i ran the TCP/ip optimiser to best settings then did an analysis. The analysis recommends that i change my RWIN to a multiple of my MSS (whatever that is), but i have no idea how to change my RWIN as the tool doesnt do it for me  Help much apreiciated.

Trying to optimise this for gaming (i.e. low pings) so not sure what to do about MTU either.

Results of analysis below, thanks very much for any help.





« SpeedGuide.net TCP Analyzer Results »
Tested on: 06.25.2007 07:56
IP address: 91.135.x.xxx

TCP options string: 0204058c0103030301010402
MSS: 1420
MTU: 1460                                                                   <-----(set to 1500 on modem)  (MRU set to 1492)
TCP Window: 514352 (NOT multiple of MSS)
RWIN Scaling: 3
Unscaled RWIN : 64294
Reccomended RWINs: 65320, 130640, 261280, 522560
BDP limit (200ms): 20574kbps (2572KBytes/s)
BDP limit (500ms): 8230kbps (1029KBytes/s)
MTU Discovery: ON
TTL: 44
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

[Rik]

TCP Optimizer should change both MTU and RWIN for you, just make sure you have the right network card selected at the time. You need to re-boot for the changes to take effect.

These settings will have no real effect on pings. Try using an MTU of 1500, and then use Optimizer to automatically test for the largest setting. It's important that, before you start, your router is set to an MTU of 1500, otherwise it will act as a bottleneck.

If you still can't change the RWIN, let me know and I'll post a screenshot.

[Rik]

In case you're not back until after I've gone offline this evening, here's a screenshot of TCP Optimizer. I have highlighted the important entries:

1) should be the network adapter you are using, for good measure, check the 'Modify All' option.

2) set MTU in this box. Start with 1500 (router needs to be the same) and, once you have applied changes and re-booted, run Optimizer again, select the Largest MTU tab, and allow it to recommend a value for you. I've found 1458, 1460 and 1500 all work well on IDNet. Latterly, I've found the best results with 1500.

3) set RWIN in this box. RWIN needs to be a multiple of MSS (maximum segment size), which is MTU-40.

Note that you should have Windows scaling checked for any value of RWIN >65535.

HTH

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