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Proxomitron reduces RWIN to 32768
Nov. 12, 2005, 02:18 AM
Post: #79
 
laighleas Wrote:Ta! It's for Server 2003 rather than XP sp2, but useful.

Check the first paragraph on that page:

Quote:Except where noted, the TCP/IP implementation for Windows XP is the same as that for Windows Server 2003.

laighleas Wrote:Now if Windows can send larger packets than Proxomitron can handle, the latter is going to have to fragment the packets.

Proxo doesn't seem to be affecting the Maximum Segement Size (MSS) reported to the server. Since I connect to the internet via my lan, my MSS is 1460, which is the MSS value I see. For Dial up, it should be 536, but I can't verify that. Also with XP, if EnablePMTUDiscovery is disabled, XP sets it to 536.

Quote:EnablePMTUDiscovery

Key: Tcpip\Parameters

Value Type: REG_DWORD?Boolean

ValidRange: 0, 1 (false, true)

Default: 1 (true)

Description: When this parameter is set to 1 (true) TCP attempts to discover the Maximum Transmission Unit (MTU), or largest packet size, over the path to a remote host. By discovering the Path MTU (PMTU) and limiting TCP segments to this size, TCP can eliminate fragmentation at routers along the path that connect networks with different MTUs. Fragmentation adversely affects TCP throughput and network congestion. Setting this parameter to 0 (not recommended) causes an MTU of 576 bytes to be used for all connections that are not to destinations on a locally attached subnet.


laighleas Wrote:Proxomitron seems to have been optimised for dial-up connections

I agree.

laighleas Wrote:About the only way round this would be to increase the size of packets that Proxomitron can send and receive - RFC 1323 allows for receive windows of up to 1 Gb.

While it may be possible to fake xp into using a larger MTU, I doubt any routers will pass frames larger than 1500 bytes, resulting in fragmentation. You can increase the size of the receive buffer up to 1GB, but this brings us right back where we are now. No matter what registry setting I have for the window size, proxo sets it to 32768.

Peakaboo Wrote:So is the TCPIP Analyzer result misleading for XP home SP2 with proxomitron and maybe should carry a notice or included in "faqs".

For me, the window size reported at http://www.speedguide.net:8117/ are correct. I have verified this with Ethereal, using XP Pro, SP2.

Peakaboo Wrote:It may be instructive to understand what makes XP home SP2 config. different from all the other win o/s especially XP Pro with SP2 which do not have this issue.

As I noted above, I use XP Pro SP2 and have the issue. In fact, I find it hard to believe that users of other win os's don't have this problem. As has been noted before, the results at dslreports are different than those reported by speedguide, with the same settings. Speedguide is looking at the TCP header, I don't know what bbr is looking at since you need sun java to test, and I don't have it.

Any test that does not report the rwin as advertised via the TCP header is meaningless.

Mike
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Messages In This Thread
Proxomitron reduces RWIN to 32768 - Tony Tough - Oct. 19, 2005, 06:12 AM
RE: Proxomitron reduces RWIN to 32768 - JJoe - Jan. 10, 2007, 04:09 AM
RE: Proxomitron reduces RWIN to 32768 - Guest - Sep. 28, 2008, 07:17 PM
RE: Proxomitron reduces RWIN to 32768 - Mele20 - Sep. 29, 2008, 12:07 PM
RE: Proxomitron reduces RWIN to 32768 - Kye-U - Sep. 30, 2008, 05:54 PM
RE: Proxomitron reduces RWIN to 32768 - Kye-U - Oct. 09, 2008, 12:22 AM
RE: Proxomitron reduces RWIN to 32768 - Guest - Oct. 14, 2008, 03:16 PM
[] - Kye-U - Oct. 19, 2005, 09:23 PM
[] - elshaddai - Oct. 20, 2005, 12:13 AM
[] - Kye-U - Oct. 20, 2005, 05:00 AM
[] - Guest - Oct. 20, 2005, 06:13 AM
[] - Tony Tough - Oct. 20, 2005, 06:15 AM
[] - Peakaboo - Oct. 20, 2005, 05:27 PM
[] - Kye-U - Oct. 20, 2005, 07:52 PM
[] - Oddysey - Oct. 21, 2005, 07:50 AM
[] - Tony Tough - Oct. 21, 2005, 08:19 AM
Same problem under windows98SE - mambo - Oct. 21, 2005, 08:27 AM
[] - Ralph - Oct. 21, 2005, 12:11 PM
[] - Tony Tough - Oct. 21, 2005, 12:24 PM
[] - Peakaboo - Oct. 21, 2005, 12:39 PM
[] - mambo - Oct. 21, 2005, 12:46 PM
[] - mambo - Oct. 21, 2005, 01:20 PM
[] - Peakaboo - Oct. 21, 2005, 01:40 PM
[] - elshaddai - Oct. 21, 2005, 04:45 PM
Cable Modem - mozerd - Oct. 21, 2005, 05:52 PM
Re: Cable Modem - Peakaboo - Oct. 21, 2005, 06:36 PM
[] - Kye-U - Oct. 21, 2005, 07:43 PM
[] - Kye-U - Oct. 21, 2005, 07:44 PM
Re: Cable Modem - Guest - Oct. 23, 2005, 09:56 PM
Re: Cable Modem - mozerd - Oct. 23, 2005, 11:24 PM
Re: Cable Modem - Guest - Oct. 24, 2005, 02:54 AM
Re: Cable Modem - Tony Tough - Oct. 24, 2005, 05:43 PM
[] - Tony Tough - Oct. 24, 2005, 06:00 PM
[] - hpguru - Oct. 24, 2005, 09:18 PM
[] - Guest - Oct. 24, 2005, 09:35 PM
[] - Guest - Oct. 24, 2005, 09:40 PM
[] - z12 - Oct. 24, 2005, 09:59 PM
[] - Peakaboo - Oct. 24, 2005, 10:24 PM
[] - hpguru - Oct. 24, 2005, 10:30 PM
[] - Guest - Oct. 24, 2005, 10:35 PM
[] - Guest - Oct. 24, 2005, 10:38 PM
[] - Guest - Oct. 25, 2005, 04:11 AM
[] - Guest - Oct. 25, 2005, 04:22 AM
[] - hpguru - Oct. 25, 2005, 07:47 AM
[] - z12 - Oct. 25, 2005, 12:38 PM
[] - ProxRocks - Oct. 25, 2005, 12:38 PM
[] - z12 - Oct. 25, 2005, 01:01 PM
[] - ProxRocks - Oct. 25, 2005, 01:17 PM
[] - Tony Tough - Oct. 25, 2005, 01:21 PM
[] - z12 - Oct. 25, 2005, 01:43 PM
[] - Peakaboo - Oct. 25, 2005, 02:06 PM
[] - hpguru - Oct. 25, 2005, 02:53 PM
[] - JJoe - Oct. 25, 2005, 04:45 PM
[] - mambo - Oct. 25, 2005, 05:09 PM
[] - z12 - Oct. 26, 2005, 01:23 AM
[] - Peakaboo - Oct. 26, 2005, 02:16 AM
[] - z12 - Oct. 26, 2005, 10:21 AM
[] - Oddysey - Oct. 26, 2005, 07:54 PM
[] - z12 - Oct. 26, 2005, 11:46 PM
[] - Oddysey - Oct. 27, 2005, 03:09 AM
[] - z12 - Oct. 27, 2005, 02:31 PM
[] - Peakaboo - Oct. 30, 2005, 01:41 AM
[] - WildTbag - Oct. 31, 2005, 12:45 AM
[] - Oddysey - Oct. 31, 2005, 02:41 AM
[] - ProxRocks - Oct. 31, 2005, 01:30 PM
[] - laighleas - Nov. 04, 2005, 12:36 PM
[] - laighleas - Nov. 04, 2005, 12:52 PM
[] - laighleas - Nov. 04, 2005, 02:02 PM
[] - Peakaboo - Nov. 04, 2005, 03:17 PM
[] - JJoe - Nov. 04, 2005, 06:08 PM
[] - Kye-U - Nov. 04, 2005, 08:50 PM
[] - ProxRocks - Nov. 04, 2005, 09:39 PM
[] - Peakaboo - Nov. 05, 2005, 03:33 AM
[] - z12 - Nov. 06, 2005, 02:37 PM
[] - laighleas - Nov. 09, 2005, 07:43 PM
[] - laighleas - Nov. 09, 2005, 07:50 PM
[] - JJoe - Nov. 09, 2005, 10:28 PM
[] - laighleas - Nov. 10, 2005, 03:03 AM
[] - JJoe - Nov. 10, 2005, 05:45 AM
[] - z12 - Nov. 10, 2005, 10:56 AM
[] - laighleas - Nov. 10, 2005, 12:18 PM
[] - laighleas - Nov. 10, 2005, 12:52 PM
[] - laighleas - Nov. 10, 2005, 01:05 PM
[] - Peakaboo - Nov. 11, 2005, 07:04 PM
[] - z12 - Nov. 12, 2005 02:18 AM
[] - laighleas - Nov. 12, 2005, 03:55 AM
[] - laighleas - Nov. 12, 2005, 04:56 AM
[] - z12 - Nov. 13, 2005, 07:26 AM
[] - Peakaboo - Nov. 13, 2005, 04:59 PM
[] - z12 - Nov. 13, 2005, 08:34 PM
[] - Oddysey - Nov. 13, 2005, 08:40 PM
[] - Peakaboo - Nov. 13, 2005, 09:23 PM
[] - z12 - Nov. 13, 2005, 10:43 PM
[] - Peakaboo - Nov. 14, 2005, 03:12 AM
[] - laighleas - Nov. 14, 2005, 03:36 PM
[] - Guest - Nov. 14, 2005, 04:32 PM
[] - Oddysey - Nov. 14, 2005, 07:47 PM
[] - Kye-U - Nov. 15, 2005, 12:07 AM
[] - z12 - Nov. 15, 2005, 05:14 PM
[] - Kye-U - Nov. 16, 2005, 06:20 AM
[] - laighleas - Nov. 26, 2005, 03:25 PM
RE: Proxomitron reduces RWIN to 32768 - JJoe - Nov. 26, 2005, 09:55 PM
[] - laighleas - Nov. 27, 2005, 02:16 AM
[] - Kye-U - Nov. 27, 2005, 02:37 AM
[] - Siamesecat - Nov. 27, 2005, 06:50 AM
[] - JJoe - Nov. 27, 2005, 08:25 AM
[] - Peakaboo - Nov. 28, 2005, 03:26 AM
[] - Kye-U - Nov. 28, 2005, 05:00 AM
[] - JJoe - Nov. 28, 2005, 06:17 AM
[] - Siamesecat - Nov. 28, 2005, 07:04 AM
[] - JJoe - Nov. 28, 2005, 01:53 PM
[] - Peakaboo - Nov. 28, 2005, 02:22 PM
[] - JJoe - Nov. 28, 2005, 03:30 PM
[] - JJoe - Nov. 28, 2005, 05:00 PM
[] - Kye-U - Nov. 28, 2005, 09:30 PM
[] - Siamesecat - Nov. 29, 2005, 08:02 AM
[] - JJoe - Nov. 29, 2005, 04:33 PM
[] - Siamesecat - Nov. 29, 2005, 08:14 PM
[] - JJoe - Nov. 30, 2005, 04:49 AM
[] - JJoe - Nov. 30, 2005, 05:12 AM
[] - Siamesecat - Nov. 30, 2005, 07:19 AM
[] - Guest - Nov. 30, 2005, 10:40 AM
[] - toods - Nov. 30, 2005, 12:45 PM
[] - JJoe - Nov. 30, 2005, 03:31 PM
[] - Tony Tough - Nov. 30, 2005, 03:56 PM
[] - Siamesecat - Dec. 01, 2005, 06:34 AM
[] - JJoe - Dec. 01, 2005, 03:33 PM
[] - laighleas - Dec. 01, 2005, 11:45 PM
[] - JJoe - Dec. 02, 2005, 12:56 AM
[] - Oddysey - Dec. 02, 2005, 12:59 AM
[] - Siamesecat - Dec. 02, 2005, 08:23 AM
[] - peakaboo g - Dec. 02, 2005, 02:50 PM
[] - JJoe - Dec. 02, 2005, 03:34 PM
[] - laighleas - Dec. 02, 2005, 04:58 PM
[] - laighleas - Dec. 02, 2005, 05:00 PM
[] - JJoe - Dec. 02, 2005, 11:35 PM
[] - Oddysey - Dec. 03, 2005, 12:03 AM
[] - laighleas - Dec. 03, 2005, 12:13 AM
[] - Siamesecat - Dec. 03, 2005, 07:15 PM
[] - Siamesecat - Dec. 04, 2005, 01:46 AM
[] - JJoe - Dec. 04, 2005, 04:46 AM
[] - Siamesecat - Dec. 04, 2005, 07:06 AM
[] - JJoe - Dec. 04, 2005, 06:11 PM
[] - Siamesecat - Dec. 05, 2005, 06:44 AM
[] - JJoe - Dec. 05, 2005, 09:48 PM
[] - Siamesecat - Dec. 06, 2005, 06:23 AM
[] - JJoe - Dec. 06, 2005, 09:33 PM
[] - Siamesecat - Dec. 07, 2005, 06:00 AM

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