Mnosteele, Need a Explanation.

SICMF · Post by **SICMF** » Sun Dec 21, 2003 3:57 pm

I'm a Beta tester on the SP2 and after this latest update i now have IE 6.05 and a change to my reg settings. Through all speed tests, I'm lighting them up and pages load in a instant. Have a look at this TCP/IP test and the speed test results and let me know what you think about these settings that have replaced my old settings. This is the Beta Machine, My main PC is using the settings from j79lr's page with my average Latency at 35ms and running well under this rig. Any Ideas?

Thanks.

BTW, This is:
Comcast Standard Package 3000/256 on XP Pro SP2.

TCP options string = 020405b40103030201010402
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.

Default Receive Window (RWIN) = 146000
RWIN Scaling (RFC1323) = 2 bits (scale factor of 4)
Unscaled Receive Window = 36500

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)
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: 5840 kbps (730 KBytes/s) @ 200ms
Your RcvWindow limits you to: 2336 kbps (292 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 49 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 11110000

Precedence (priority) = 000 (routine)
Delay = 0 (normal delay)
Throughput = 1 (high throughput)
Reliability = 1 (high reliability)
Cost = 1 (low cost)

SBC Southfield:
Your Throughput

Download = 3.507 Mbps
Upload = 242.42 kbps

Blue Marble Chicago:
2003-12-21 15:45:57 EST: 3304 / 243
Your download speed : 3304711 bps, or 3304 kbps.
A 403.4 KB/sec transfer rate.
Your upload speed : 243813 bps, or 243 kbps.
Seems like broadband .. above the 1mbit barrier!

FTP AOL:

I hold from start to finish in the 400KB to 415KB range

mnosteele52 · Post by **mnosteele52** » Sun Dec 21, 2003 4:09 pm

Comcast must be giving you an early Christmas gift

. As you see your speeds are above your caps, so my assumption is that Comcast is actually giving you 3500 instead of 3000. In any case your browser has no effect on your bandwidth and your ftp test is excellent. In my opinion there really is no benefit of using a TcpWindowSize larger than 64240 unless your caps are over 5000-6000 and you have high latency. Actually I think unless a value of over 100000 is warranted then it doesn't benefit one to enable WindowsScaling, that is just my opinion from my experience. Try a value of 64240 and I bet you yield the same results.

SICMF · Post by **SICMF** » Sun Dec 21, 2003 4:27 pm

Originally posted by mnosteele52
Comcast must be giving you an early Christmas gift . As you see your speeds are above your caps, so my assumption is that Comcast is actually giving you 3500 instead of 3000. In any case your browser has no effect on your bandwidth and your ftp test is excellent. In my opinion there really is no benefit of using a TcpWindowSize larger than 64240 unless your caps are over 5000-6000 and you have high latency. Actually I think unless a value of over 100000 is warranted then it doesn't benefit one to enable WindowsScaling, that is just my opinion from my experience. Try a value of 64240 and I bet you yield the same results.

Alright Perfect. I'll give it a shot. It's just getting me how my other PC which is almost the same rig, and i'm pulling around 2700-2900 on the tests and a unsteady 315-325 with the FTP test. And thats the settings from jlr79. ??? Not complaning though.

Thanks.

j79zlr · Post by **j79zlr** » Sun Dec 21, 2003 10:56 pm

What did I do?

My page would only calculate a RWIN that high if you had a latency of 385ms which is probably way to high.

SICMF · Post by **SICMF** » Mon Dec 22, 2003 4:30 am

Originally posted by j79zlr
What did I do?

My page would only calculate a RWIN that high if you had a latency of 385ms which is probably way to high.

No, after the update for SP2, it changed my settings to these current ones. They are working great, just curious why. My main rig is the one using your settings which are the correct ones, but with these i have full throttle. That is what i was asking, These current settings don't add up, but i have to put one foot on the PC when i click a web page , Just in case.

Still breaking it down trying to figure out what settings were changed. Lots of changes to code is this pack and the OS seems alot lighter.