Help with my RWIN

[mrproper]

I have read that RWIN parameter is very important for the connection. I don't understand very much, so I need help.

First of all, I have read somewhere that you must put your download and upload speeds (bandwidth) and the delay (latency) and the formula gives you the result (rwin). I don't know which speeds to set. The theorical of my ISP (down 20 Mb, up 1 Mb) or the speeds I can read in my router (Down Stream 8875 Kbps, Up Stream 509 Kbps)?

And what about the delay or latency? I have two.  If I use TCPOptimizer program gives me a maximum of 480, but If I do a tracert to a web (for example, "tracert testmy.net") while I am downloading a large file, I get one of 300 more or less.

On the other hand, the speeds I can read in my router are the maximum I can get? That is to say, can I download at more than 8875 Kbps? or is it the top I can reach?

Thank you very much

[FallowEarth]

Hi mrproper. You might be interested in using Cablenut to tweak your TCP settings, like RWIN. You can check out our guide: http://www.testmy.net/forum/t-1013. There are also pre-compiled cablenut files in the zip files titled "VanBuren's Cablenut Settings."

RWIN refers to the TCP setting known as Default Receive Window. This is an assigned value which defines the maximum (scaled) number of bytes that your PC can handle at one time in network traffic.

[mrproper]

As I told in my previous message I have used Cable Nut to tweack all my connection (RWIN included). But when I have read in other web pages about RWIN and saw the different values for that parameter, it's when I have benn investigating. That is to say, the value in CableNut was very different than I read in internet (according to bandwidth and delay that are not considered in Cablenut).

Anyway, If I use this link to optimize my connection

http://www.j79zlr.com/cablenutXP2k.php (it's inside your link)

I put "Enter MTU" = 1496, and what about Download, Upload and Latency? (that is what I was asking in the previous post).

Thanks

[cholla]

mrproper ;I think you will find quite a bit about RWIN setting & some other tweaks in the links below.There are more links in some of them you might want to check.Routers are not my forte but it does seem it may be limiting your speed.If what you are supposed to be getting is 20Mbdown &1 Mb up unless I misunderstood.If you can try a time when more members are on.

http://www.testmy.net/forum/index.php?topic=11218.msg111408#msg111408

http://www.testmy.net/forum/index.php?topic=8555.msg83659#msg83659

http://www.testmy.net/forum/index.php?topic=5117.msg47780#msg47780

http://www.testmy.net/forum/index.php?topic=11149.msg110277#msg110277

http://www.testmy.net/forum/index.php?topic=5117.msg47780#msg47780

http://www.testmy.net/forum/t-9452.0

http://smallvoid.com/tweak/winnt/network.html#AFD_WINDOW

[FallowEarth]

Download and upload you will have to get from your ISP if you don't already know.

Easiest way to find latency is to download a large file (>=200MB) and run a traceroute to that site. Your latency will be shown as the highest time in the traceroute.

Your MTU should likely be 1500.

[mrproper]

FallowEarth:

TCPOptimizer gives me as optimal settings:

- MTU = 1496

- Latency (maximum) = 480 ms

But latency is not obtained while downloading nothing,

[cholla]

You probably just need to clear your cache between tests.This may produce more consistent results on the test.

Next you need to change your RWIN to 512512 if you want it that large this way when it scales the unscaled RWIN will be 64064 whiich is the largest you can get with the MSS you use.If you want to try a smaller RWIN then you need to use 256256 so the unscaled RWIN will remain as large as possible.

I need to check this & it will change the RWIN from what I suggested .The point is you want it to have the unscaled RWIN as large as possible but under 65535 & based on the MSS.I think with DSL your MTU needs to be 1492 which means your MSS would be 1452 .This would make the RWIN  63888 unscaled & 511104 for the setting.

For this setting in Cablenut you need to read the TOS .text file I'm putting in below.

DefaultTOSValue

I'm also putting in a .txt file that has the MS explanation of what a lot of the CN settings do.

[mrproper]

You probably just need to clear your cache between tests.This may produce more consistent results on the test.

Next you need to change your RWIN to 512512 if you want it that large this way when it scales the unscaled RWIN will be 64064 whiich is the largest you can get with the MSS you use.If you want to try a smaller RWIN then you need to use 256256 so the unscaled RWIN will remain as large as possible.

I need to check this & it will change the RWIN from what I suggested .The point is you want it to have the unscaled RWIN as large as possible but under 65535 & based on the MSS.I think with DSL your MTU needs to be 1492 which means your MSS would be 1452 .This would make the RWIN  63888 unscaled & 511104 for the setting.

For this setting in Cablenut you need to read the TOS .text file I'm putting in below.

DefaultTOSValue

I'm also putting in a .txt file that has the MS explanation of what a lot of the CN settings do.

Sorry, but my english is a little limited. Moreover I don't understand very much about connections, etc.

So, I have understood this:

1. I do the speed test. If I want to repeat I have to clear my cache.

2. Change RWIN to 512512, so my Unscaled TCP Receive Window will be equal to 64064 (the largest I can get with my current MSS).

3. You think that my ADSL needs a MTU of 1492. My connection is ADSL2+, based on pppoA protocol, so maximum MTU es 1500. TCPoptimizer tells me a maximum (and optimum) MTU of 1496. I think that maximum MTU in pppoE is 1492 (in pppoA is 1500).

4. I don't undersand what 's better: MTU=1492 or 1496?

5. I don't understand anything about the files you have attached. What do you mean?

Than you very much for you interest

[dlewis23]

mrproper change your MTU to 1492, and use TCPoptimizer and set it to 20000kbps, restart and do this test http://www.testmy.net/tools/test/d_load.php?&st=st&tt=1&ta=1&top=000&out_src=20MB

[mrproper]

mrproper change your MTU to 1492, and use TCPoptimizer and set it to 20000Kbps, restart and do this test http://www.testmy.net/tools/test/d_load.php?&st=st&tt=1&ta=1&top=000&out_src=20MB

Do I set the speed in TCPOptimizer to 20000 kbps? My current speed in the router (adsl status) is 9000 kbps. And TCPOptimizer is telling me that optimum MTU is 1496.

I do whatever you sayl me, because you are trying to help me. But I want to understand the things I do.

Thank you

[dlewis23]

Do I set the speed in TCPOptimizer to 20000 kbps? My current speed in the router (adsl status) is 9000 kbps. And TCPOptimizer is telling me that optimum MTU is 1496.

I do whatever you sayl me, because you are trying to help me. But I want to understand the things I do.

Thank you

set it to 9500kbps i dont know why i thought 20000kbps. and set the MTU to 1492.

[cholla]

mrproper ;I didn't mean to go above your technecal level I thought you had the Cablenut program.

I'm not as familiar with using TCP optimizer.& need to find out more of how it sets RWIN to suggest the RWIN to use with it.

I do know that with DSL the MTU is 1492.

the test detected this as 1 of your RWIN settings Default TCP Receive Window (RWIN) = 538720

In windows XP this should be based on AFD parameters.I think your page size is 4096 & the

Default TCP Receive Window (RWIN) should be a multiple of that.Your page size could be 8192.

But lets assume for now it is 4096 so set your  Rwin at 532480 this would be close to the size the tcpip analyzer detected.Then test & see how your system performs.

dlewis23 or FallowEarth; do either of you know which TCP Optimizer uses for sure on the RWIN setting it uses.If it uses the MSS to calculate & set the RWIN more like a 9X OS or the AFD parameters based on page size?

[dlewis23]

dlewis23 or FallowEarth; do either of you know which TCP Optimizer uses for sure on the RWIN setting it uses.If it uses the MSS to calculate & set the RWIN more like a 9X OS or the AFD parameters based on page size?

If i remember correctly it uses AFD parameters to get the RWIN. But i could be wrong.

[cholla]

dlewis23;I was going by what  mrproper posted .Below is his TCP Optimizer settings or the recomendations it made.the RWIN 538720 would be based on MSS of 1456.

TCPOptimizer:

Largest MTU=1496

Maximum latency=486 ms

BDP=539156 --> making it a multiple of MSS (1456) ---> RWIN=538720

TCP Receive Windows=513920 ---> corrected to 538720

None of the RWIN's he had are a multiple of 4096 or 8192.I think these are the muliples that AFD uses .There may be some more.

This is how I understand AFD works for figuring RWIN.

The AFD-Windows should be rounded to a multiple of page size(Usually 4096 Bytes). Not a multiple of the Maximum Segment Size(MSS) which is recommended for the TCPIP-Window.

The processor manages the mapping in terms of pages of 4 Kilobytes each - a size that has implications for managing virtual memory by the system.

These are registry settings that are in Cablenut or in the registry if you do your own.

These two below should be based on AFD parameters

DefaultReceiveWindow

DefaultSendWindow

These two should below be multiples of MSS

GlobalMaxTcpWindowSize

TcpWindowSize

Do you know what BDP is?

[dlewis23]

Do you know what BDP is?

yea its a way to figure out the RWIN, you mulptly your bandwidth by your Ping time and if get your RWIN.

[mrproper]

Sorry for not participating in my own post !!  It was so interesting !! but I din

[dlewis23]

ok try both these files

[cholla]

dlewis23 ;I still think that DSL should use MTU 1492 both the css files have the MSS at 1460.

TcpRecvSegmentSize    1460

TcpSendSegmentSize  1460

All I really see is the numbers since I have ME but I have the XP Cablenut list & I know this is where this setting goes.

That would be for MTU 1500.

The css file for DSL should have 1452 I beleive.

[dlewis23]

dlewis23 ;I still think that DSL should use MTU 1492 both the css files have the MSS at 1460.

TcpRecvSegmentSize    1460

TcpSendSegmentSize  1460

All I really see is the numbers since I have ME but I have the XP Cablenut list & I know this is where this setting goes.

That would be for MTU 1500.

The css file for DSL should have 1452 I beleive.

I still think it should be a 1492 as well. The reason the MSS is 1460 in both, is because there is almost no difference in a mtu of 1492 nad 1496.

this is what i used to make those files http://www.j79zlr.com/cablenutXP2k.php

[mrproper]

Hello Vanburen:

You helped me very much a long time ago, but now I have changed my connection type (same ISP) and I need help. I opened a post (http://www.testmy.net/forum/t-15534) to find out a RWIN value that suits me. They are helping me very much (dlewis23, cholla and FallowEarth. They are fantastic members) but at the end I have been given two .ccs files made with the program "j79zlr".

Before applying any .ccs file of your own program, I prefer to follow all the steps you posted in http://www.testmy.net/forum/t-2097, so perhaps you can help me with my suitable .ccs file.

I hope that they (cholla, dlewis23 and FallowEarth) don't get angry with me.

** 1) OS: Windows XP Proffesional (SP2 installed).

Doownloaded and installed the p2p fix for SP2 (german version because the english one didn't work).

** 2) ISP: ya.com (Spain)

I live in Spain and my connection is:

ADSL2+ (PPPoA protocol, not PPPoE)

Advertised speeds:

Down: "until" 20 Mb, Up: 1 Mb

Real speeds (according my distance to the central, etc):

Down: 9000 kbps (seen in my router, in ADSL Status)

Up: 509 kbps (seen in my router, in ADSL Status)

** 3) I have installed "TCPOptimizer" and gives me an optimum MTU=1496. Now I have these values in "speedguide.net" test:

TCP options string = 020405b00103030301010402

MTU = 1496

MTU is fully optimized for broadband.

MSS = 1456

Maximum useful data in each packet = 1456, which equals MSS.

Default TCP Receive Window (RWIN) = 522720

RWIN Scaling (RFC1323) = 3 bits (scale factor of 6)

Unscaled TCP Receive Window = 65340

For optimum performance, consider changing RWIN to a multiple of MSS.

Other RWIN values that might work well with your current MTU/MSS:

512512 (MSS x 44 * scale factor of

256256 (MSS x 44 * scale factor of 4)

128128 (MSS x 44 * scale factor of 2)

64064 (MSS x 44)

bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 20908.8 kbps (2613.6 KBytes/s) @ 200ms

Your TCP Window limits you to: 8363.52 kbps (1045.44 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 55 hops

TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349) = 11110000 (240)

Precedence (priority) = 111 (Network Control)

Delay = 1 (low delay)

Throughput = 0 (normal throughput)

Reliability = 0 (normal reliability)

Cost = 0 (normal cost)

Check bit = 0 (correct, 8th checking bit must be zero)

DiffServ (RFC 2474) = No valid DiffServ equivalent. See the TCP Optimizer documentation, or RFCs 2474, 2475, 2597, 2598, 2873.

I have changed RWING to 512512 as suggested but I don't get better results, but if you want I can change it again.

** 4) These are the results of my speed tests, but I live in Spain so I don't know if they are suitable (any suggested speedtest?)

:::.. Download Stats ..:::

Download Connection is:: 4557 Kbps about 4.56 Mbps (tested with 12160 kB)

Download Speed is:: 556 kB/s

Tested From:: https://testmy.net/ (Server 2)

Test Time:: 2006/08/10 - 1:34pm

Bottom Line:: 79X faster than 56K 1MB Download in 1.84 sec

Tested from a 12160 kB file and took 21.86 seconds to complete

Download Diagnosis:: Looks Great : 5.8 % faster than the average for host (185.76)

D-Validation Link:: https://testmy.net/stats/id-W5OKGL8XE

User Agent:: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Maxthon; .NET CLR 1.1.4322) [!]

Not very bad, but it isn't my normal speed !!

TCP/Web100 Network Diagnostic Tool v5.3.3d

click START to begin

Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done

running 10s outbound test (client to server) . . . . . 455.87Kb/s

running 10s inbound test (server to client) . . . . . . 1.08Mb/s

Your PC is connected to a Cable/DSL modem

Information: Other network traffic is congesting the link

I have made the tests again and these are the results:

:::.. Download Stats ..:::

Download Connection is:: 3830 Kbps about 3.83 Mbps (tested with 5983 kB)

Download Speed is:: 468 kB/s

Tested From:: https://testmy.net/ (Server 2)

Test Time:: 2006/08/10 - 1:44pm

Bottom Line:: 67X faster than 56K 1MB Download in 2.19 sec

Tested from a 5983 kB file and took 12.796 seconds to complete

Download Diagnosis:: May need help : running at only 87.14 % of your hosts average (185.76)

D-Validation Link:: https://testmy.net/stats/id-V04MKFN38

User Agent:: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Maxthon; .NET CLR 1.1.4322) [!]

TCP/Web100 Network Diagnostic Tool v5.3.3d

click START to begin

Another client is currently being served, your test will begin within 45 seconds

Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done

running 10s outbound test (client to server) . . . . . 343.59Kb/s

running 10s inbound test (server to client) . . . . . . 1.16Mb/s

Your PC is connected to a Cable/DSL modem

I have downloaded the tracert and ping program and these are the results:

Microsoft Windows XP [Versi

[mrproper]

Well... no discussion...

If you don't mind I think I am going to ask for Vanburen a .css file. Let's start in the begining. I will do all the steps he tells in http://www.testmy.net/forum/t-2097 and paste all the results. Perhaps you reach easier conclusion with more results. The new post that I have opened is http://www.testmy.net/forum/t-15602.

Thanks again

[VanBuren]

try this file, its from version 9 of my tweakfiles.

also test speed here http://cemp1.switch.ch/network/performance/web100/tcpbw100.html

make a tracert against that site aswell

VanBuren

[mrproper]

Hi, I have made everything several times before apllying you file and after applying it, so that you can compare the results:

*** Test results (3 times) against http://cemp1.switch.ch/network/performance/web100/tcpbw100.html before doing anything:

TCP/Web100 Network Diagnostic Tool v5.3.3e

click START to begin

Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done

running 10s outbound test (client to server) . . . . . 478.41Kb/s

running 10s inbound test (server to client) . . . . . . 7.16Mb/s

Your PC is connected to a Cable/DSL modem

Information: Other network traffic is congesting the link

click START to re-test

Another client is currently being served, your test will begin within 90 seconds

Another client is currently being served, your test will begin within 45 seconds

Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done

running 10s outbound test (client to server) . . . . . 478.97Kb/s

running 10s inbound test (server to client) . . . . . . 6.82Mb/s

Your PC is connected to a Cable/DSL modem

Information: Other network traffic is congesting the link

click START to re-test

Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done

running 10s outbound test (client to server) . . . . . 478.97Kb/s

running 10s inbound test (server to client) . . . . . . 7.27Mb/s

Your PC is connected to a Cable/DSL modem

Information: Other network traffic is congesting the link

*** Tracert against http://cemp1.switch.ch/network/performance/web100/tcpbw100.html before doing anything:

Traza a la direcci

[VanBuren]

the MTU is off, since your on PPPoA the MTU should be 1500

read the manual for your router/modem and see if you can set MTU manually to 1500

you show packetloss here

1    <1 ms    <1 ms    <1 ms  192.168.1.1

  2    *      43 ms    *    framed-user-32.62.151.30.ya.com [62.151.30.32]

thats between your modem/router and CO. If you use a phone extension wire, try replace it or bypass it and connect modem/router direct to your house main phone socket.

VanBuren

[cholla]

Hey VanBuren:Time for a tutorial for me.

The MTU for ADSL with PPPoA is supposed to be 1500 like cable broadband?

The MTU for DSL & possibly ADSL with PPPoE is supposed to be 1492 ?

If I have those correct now please explain why.

mrproper's MTU & MSS have tested off in this & the other post at least with the TCPIP analyzer test.They show MTU1496 & MSS 1456.

I wanted to ask is the TCPIP analyzer test At speedguide.net any good for Windows XP It seems to be more for 9X OS's. The RWIN it reads seems to be MSS based instead of AFD parameter based.

mrproper : Theres no problem with seeking more help & VanBuren knows a lot about these settings.That's why I'm asking him to explain this better to me so I can help someone better the next time.