Optimize-need help

[Topus]

Here's my info.
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Dsl PPPoe
Seed-2000/256
XP(sp2)
Current settings

SpeedGuide.net TCP/IP Analyzer


TCP properties for IP = xxx.xxx.xxx.xxx ()
Browser/OS = Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)
Notes: Read the Analyzer FAQ if the above is not your IP address.

TCP options string = 020405a001010402

MTU = 1480
MTU is optimized for Windows XP PPoE DSL broadband. If not, consider raising MTU to 1500 for optimal throughput.

MSS = 1440
MSS is optimized for Windows XP PPPoE DSL broadband. If not, consider raising your MTU value.

Default TCP Receive Window (RWIN) = 65535
RWIN Scaling (RFC1323) = 0 bits
Unscaled TCP Receive Window = 65535

Note: TCP 1323 Options need to be enabled for RWIN over 2^16 (65535). Windows 9x might also need the MS Vtcp386 fix.
For optimum performance, consider changing RWIN to a multiple of MSS.
Other RWIN values that might work well with your current MTU/MSS:
506880 (MSS x 44 * scale factor of 8)
253440 (MSS x 44 * scale factor of 4)
126720 (MSS x 44 * scale factor of 2)
63360 (MSS x 44)

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

Your TCP Window limits you to: 2621.4 kbps (327.675 KBytes/s) @ 200ms
Your TCP Window limits you to: 1048.56 kbps (131.07 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 118 hops
TTL value is ok.

Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349) = 00000000 (0)
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Only
Optimal settings-Check
Optimize All Network Adapters-Check
PPPoE-Check
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Improved nothing

Question:
Why my "MSS" is 1440 ? Should it be 1460 for Dsl PPPoE

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Please help me how to do the "Custom Settings".

Your reply will be grateful...........Thanks

[trogers]

Question:
Why my "MSS" is 1440 ? Should it be 1460 for Dsl PPPoE

-----------------------------------------------

Please help me how to do the "Custom Settings".

Your reply will be grateful...........Thanks

I think you may have been confused by MTU and MSS.

Maximum Transmission Unit (MTU) is the largest data packet size that is being transmitted and accepted in the internet.

For Cable and PPPoA system, MTU is 1500. For DSL PPPoE there are two common values used - 1492 and 1480.

Maximum Segment Size (MSS) = MTU - 40. These 40 bytes
are for the header information of each data packet. MSS carries only pure data without the header information.

You can try the 2 custom settings given to you at this thread:

http://forums.speedguide.net/showthread.php?t=206800

These 2 custom settings have only a difference. This is the TCP Receive Window - 63360 or 126720.

TCP Receive Window (RWIN) is calculated from this formula:

RWIN = Bandwidth x latency x (variation factor) / 8

Bandwidth is your ISP subscribed download speed.

Latency (or Round Trip Time, RTT) is the time taken for your signal to reach a server and then return back to you. I usually use an average latency. This average can be found by doing tracerts at different time of the day.

Variation factor is to compensate for varying internet traffic conditions. I usually use 1.5 but some other people may use 2 if traffic conditions can vary much.

Divide by 8 is to convert bandwidth (kbps) to KiloBytes (KB).

RWIN should be an even multiple of MSS. So,

RWIN = 63360 = MSS x 44 = 1440 x 44

RWIN = 126720 = MSS x 88 = 1440 x 88 Both 44 and 88 are even numbers.

When RWIN is higher than 65535, you need to check the Window Scaling in TCP Optimizer. If 65535 or less, you will leave Window Scaling uncheck.