SG TCP/IP Analyzer

conical · Post by **conical** » Fri Jun 01, 2001 11:44 am

I downloaded and run the MS Vtcp.386 fix for Windows 98. But the analyzer still reports my RWIN as 65535 when it is really set at 256960.

Before I installed the fix I renamed the c:\windows\system\Vtcp.386 file. I rebooted the system. I tried installing the fix again to no avail. I am using Win98 se. Should I have renamed the file before installing the fix? Maybe that's the reason it doesn't work?

Lobo · Post by **Lobo** » Fri Jun 01, 2001 11:51 am

Set Tcp1323Opts to 1 to enable scaling

Lobo · Post by **Lobo** » Fri Jun 01, 2001 2:30 pm

Is it working now?

conical · Post by **conical** » Fri Jun 01, 2001 4:15 pm

Originally posted by Lobo
Set Tcp1323Opts to 1 to enable scaling

My Tcp1323Opts was set to 3. I changed it to 1 and rebooted but the Analyzer still shows the RWIN at 65535. Should I reinstall the Vtcp.386 fix now?

Lobo · Post by **Lobo** » Fri Jun 01, 2001 4:17 pm

Yes and change name back to what it was

conical · Post by **conical** » Fri Jun 01, 2001 5:26 pm

Ok I deleted the "new" VTCP.386 file and renamed the old one back to the original name. I reinstalled the fix then rebooted.

Just wanted to mention that I used the fix in the past and it worked. But, I recently restored my system with a homemade recovery disk that was not set up for broadband nor did it have the VTCP fix on it -- the way my system was before I set it up for broadband and the fix the last time.

Here are my Analyzer results:

TCP options string = 020405b401010402

MTU = 1500
MTU is fully optimized for broadband.

MSS = 1460
Maximum useful data in each packet = 1460, which is equal to MSS.

Default Receive Window (RWIN) = 65535
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 65535
Note: Under Windows 9x, if you have RWIN set to any other value, and the Analyzer reports 65535 you might need to install the MS Vtcp386 fix.
For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 2621.4 kbps (327.675 KBytes/s) @ 200ms
Your RcvWindow limits you to: 1048.56 kbps (131.07 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 115 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

Any clues?

Lobo · Post by **Lobo** » Fri Jun 01, 2001 5:29 pm

Have you got proxy unchecked, help page, 2nd page at bottom

Lobo · Post by **Lobo** » Fri Jun 01, 2001 5:35 pm

Up above it says scaling is off, again set Tcp1323Opts to 1 and reboot afterwards, retest, repost

Do you have adjuster by any chance

conical · Post by **conical** » Fri Jun 01, 2001 6:23 pm

Got it!!!

The problem: My Tcp1323Opts was in hexadecimal. I changed it to a string value and presto! Thank you Lobo for all your help. Your patience and helping encouraged me not to give up. Hopefully this will help others with a similar problem.

TCP options string = 020405b40103030201010402

MTU = 1500
MTU is fully optimized for broadband.

MSS = 1460
Maximum useful data in each packet = 1460, which is equal to MSS.

Default Receive Window (RWIN) = 256960
RWIN Scaling (RFC1323) = 2 bits
Unscaled Receive Window = 64240
RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 10278.4 kbps (1284.8 KBytes/s) @ 200ms
Your RcvWindow limits you to: 4111.36 kbps (513.92 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 115 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

Lobo · Post by **Lobo** » Fri Jun 01, 2001 6:29 pm

What are your system specs, may be able to go faster

conical · Post by **conical** » Fri Jun 01, 2001 7:19 pm

From http://www.bandwidthplace.com:

From http://www.pcpitstop.com:

It seems I get "sugar-coated" results from the various speed test sites. Here is an actual download but results vary sometimes more or less depending on time of day and site:

I guess this could not be improved. I am using insight@home.

Lobo · Post by **Lobo** » Fri Jun 01, 2001 7:25 pm

What are your system specs, may be able to go faster

conical · Post by **conical** » Fri Jun 01, 2001 7:45 pm

Originally posted by Lobo
What are your system specs, may be able to go faster

Sorry, I meant to post my system specs but got wrapped up in the speed tests.

My system specs are pretty generic:

AMD K6-2/400 with 128 MB RAM, WIN98se (fat32), Linksys LNE100 NIC, Smart One CMX110 modem, SMC Barricade router, Linksys hub. I share connection with 2 other PCs. Using excite@home.