Changing the RWIN babY!

cloudy311 · Post by **cloudy311** » Thu Nov 09, 2000 8:33 pm

I've seen a post a while ago which talked about changing the rwin, but can't seem to find it. Can you tell me the steps I need to take in order to change my rwin and give me a few numbers which I can try out? I hope this isn't too tough for you studs

Venom · Post by **Venom** » Thu Nov 09, 2000 8:43 pm

Ok if you go to start and then go to run and type regedit and click on the + next to each key. this is the Key to follow.

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP

And then look for this key DefaultRcvWindow in the right window.

and you can try these numbers.

256960
327040
373760

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[This message has been edited by Venom (edited 11-09-2000).]

Brent · Post by **Brent** » Thu Nov 09, 2000 8:48 pm

http://www.speedguide.net/Cable_modems/cable_registry.shtml

Biggy · Post by **Biggy** » Fri Nov 10, 2000 12:30 am

On cablenut's program all you have to do is change the settings on that page right, i don't have to go to start, run and all that stuff do I.

spaceman · Post by **spaceman** » Fri Nov 10, 2000 1:26 pm

Hi yurka,
Needless to say, I'm neither Brent nor Venom but...just double-click on DefaultRcvWindow and enter your setting into the new window that pops-up. Click OK and exit the registry....restart and Voila!!
Good luck..
spaceman

Venom · Post by **Venom** » Fri Nov 10, 2000 2:00 pm

Yurka:

Yeap just like spaceman said

But if for some wiered reason that setting isn't there (cuz it should be in there) but if that's the case you have to add it just right clik on an empty area of the right window and select new then select string and name it DefaultRcvWindow and then double click on it and give it the value, But like I said it should already be there.

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yurka · Post by **yurka** » Sat Nov 11, 2000 12:10 am

Venom, Brent: in my Registry, it says Default in the right window under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP
Do I have to type DefaultRcvWindow=256960 or just 256960 in the New>String window? TIA.

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frustrated Yurka :-)

[This message has been edited by yurka (edited 11-10-2000).]

yurka · Post by **yurka** » Sat Nov 11, 2000 5:18 pm

Tx, guys. Just did it. Now, on the right it says: DefaltRcvWindow "256960"
It shows " ", although I never typed it. I guess, the Registery knows what it is doing. I will restart soon. If my speeds will go down, I'll try two other magic numbers, 327040 and 373760. If nothig works, I will delete the key. Right?

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frustrated Yurka :-)

haze · Post by **haze** » Sat Nov 11, 2000 5:40 pm

Originally posted by yurka:
If my speeds will go down, I'll try two other magic numbers, 327040 and 373760. If nothig works, I will delete the key. Right?

Not sure of this but if you delete the key wouldn't the Rwin setting revert to the default of 8k if it was windows98?

spaceman · Post by **spaceman** » Sat Nov 11, 2000 6:03 pm

Hi haze,
yep....that's what it'll do !!

I set mine to "0" --zero.......not default at 8192 but ZERO the other night and got some really good download speeds. I could not believe it.....some in excess of 300KB/s!
regards,
spaceman

Venom · Post by **Venom** » Sat Nov 11, 2000 6:13 pm

Spaceman

Thats COOL!!!

I'm gona have to check that one out.

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rmrucker · Post by **rmrucker** » Sat Nov 11, 2000 7:18 pm

Venom -- intriguing isn't it?
We've got to packet sniff this out and find out what really happens...

cablenut · Post by **cablenut** » Sat Nov 11, 2000 8:04 pm

I'll put up my confusing formula

(Average DL Rate In Kbits * 1024 * .2) / 8 = n

n / Mss Value = x

x * mss value ^ next rounded equal = rwin window

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Head webcheese and geek guru @ http://www.cablenut.com

Venom · Post by **Venom** » Sat Nov 11, 2000 8:17 pm

rmrucker

I'm with ya on that one, I have to test that one out tomorrow morning

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Venom · Post by **Venom** » Sat Nov 11, 2000 8:45 pm

Hey spaceman just one questions did you turn off the windows scaling (Tcp1323Opts), when you gave your RWIN a value of 0?

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spaceman · Post by **spaceman** » Sat Nov 11, 2000 8:56 pm

Venom,
My only tweak at the moment is the DefaultRcvWindow setting.

I just set it for "-8192" ...... yes minus
8192 and got this:

Download Bandwidth Test Results

Text Block Size 200 KB
Download Time 1650 ms
Transmission Speed 970 Kb/s

I know dinky test but......

spaceman

spaceman · Post by **spaceman** » Sat Nov 11, 2000 9:06 pm

just ran this one at ...minus -64240

Your Speed is: 751.4 Kbps

keeps me from taking myself too theriously!!

rmrucker · Post by **rmrucker** » Sat Nov 11, 2000 9:21 pm

Love it guys -- I just feel stupid I didn't think of it first! This is great!

Venom- we got to look at it w/ and w/o scaling, plus w/ and w/o PMTU-D. Could be interesting...

I'll try in the AM -- I'm outta here!

[This message has been edited by rmrucker (edited 11-11-2000).]

spaceman · Post by **spaceman** » Sat Nov 11, 2000 9:32 pm

OK, this is the last one....

RWIN set at -256960

Graphics Test (Results)
Loaded 225,455 bytes in 2.53 seconds.
Your throughput is 713 Kbps.

Good luck guys!!

spaceman

cloudy311 · Post by **cloudy311** » Sat Nov 11, 2000 9:57 pm

I thought I read somewhere that the rwin value affects something called "mss and mtu" (I think this is what it's called). Anyways,do i have to edit these values if I use a different rwin? If so, how can i edit the mss or mtu?

rmrucker · Post by **rmrucker** » Sun Nov 12, 2000 11:00 am

Setting RWIN "very low" results in Windows98 defaulting to 8192. See my HUGE post if you desire the gory details!

MSS and MTU are not effected by your RWIN setting.

striderf1 · Post by **striderf1** » Sun Nov 12, 2000 11:27 am

i'm in win2kpro, if i set my rwin at 0 or a negative number would it help me out?

yurka · Post by **yurka** » Sun Nov 12, 2000 3:15 pm

1. After I set DefaultRcvWindow 256960, I did not notice anything diffrent in terms of surfing, but it's been 24 hours only... and it' Sunday...
2. The settings on "3comUSB Network Interface" showed RWIN 8760 before I changed Registry, they show the same 8760 now.
Are there two different RWINs?

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frustrated Yurka :-)

Venom · Post by **Venom** » Mon Nov 13, 2000 11:37 am

Here are 2 test I made today

Well i desided to speed test what I already had wich was an RWIN of 373760.

Test running.........
** Speed 636(down)/956(up) kbps **
(At least 12 times faster than a 56k modem)
Finish.

Notice the Upload I have no clue how this hapened, but I have not been able to recreate it *LMAO*

Next the test with RWIN = 0:
Test running.......
** Speed 0(down)/297(up) kbps **
About modem speed!
Finish.

*LMAO* I ran this like 3 times and this is what I got *ROFLMAO*

Ok then I ran a tweak test on it.

* Results
* Your public IP address is xx.xxx.xx.xxx
Hops left before discard (TTL) is 116
TCPopts hex string is 020405b401010402
Max Segment Size is 1460
* Your MTU is set ok
SACK Permitted (RFC2018)
Ping stability - - - - - - - - - -
* You are not pingable
No packet loss test will be done
DefaultRcvWindow (RWIN) is 8192
Your RWIN limits you @200ms to 327kbps
* Your RWIN 8192 is too low
Your Path MTU Discovery is ON
Max sized data packet from you 1500
* Conclusion.. possible problem
* End

Ok then I changed my RWIN back to 373760 and tested it again

Test running..........
** Speed 671(down)/239(up) kbps **
(At least 13 times faster than a 56k modem)
Finish.

Now the upload stayed didn't change *lol* but I know that my upload is capped but That fist test really though me off.

Then I ran a tweak test:

* Results
* Your public IP address is xx.xxx.xx.xxx
Hops left before discard (TTL) is 116
TCPopts hex string is 020405b401010402
Max Segment Size is 1460
* Your MTU is set ok
SACK Permitted (RFC2018)
Ping stability 261 73 49 49 49 49 49 49 49 47
* Wide variation in ping, 47 to 261
* Quick packet-loss tested ok
DefaultRcvWindow (RWIN) is 65535
Your RWIN limits you @72.4ms to 7241kbps
Your RWIN limits you @200ms to 2621kbps
* Your RWIN is set ok at 65535
Your Path MTU Discovery is ON
Max sized data packet from you 1500
* Conclusion.. HEALTHY SETUP!
* End

interesting ins't it!

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YARDofSTUF · Post by **YARDofSTUF** » Mon Nov 13, 2000 3:08 pm

hey Venom, "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP

And then look for this key DefaultRcvWindow in the right window."
I dont have this item there.

Storm90 · Post by **Storm90** » Tue Nov 14, 2000 9:55 pm

Yardstuff, you useally don't have it in your reg to you enter it. It is not part of windows. You will have to add this key if you want it. Hope this helps!