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Thread: Phillip

  1. #1
    Lobo
    Guest

    Post Phillip

    Phillip, just playing I changed my RWIN to 474500, here is pcpitstop:
    Bandwidth Down 2857 Kbits/sec
    Bandwidth Up 132 Kbits/sec
    Average Ping 55 ms
    Ping Loss 0%
    TCP Receive Window 474500
    External IP Address 24.
    Internal IP Address 24.
    Browser MSIE 5.5; Win 9x 4.90
    IE current cache 1 MB
    IE max cache 15 MB

    Now next I will post yours, it slows RWIN of 474496, whats up

    [ 03-11-2001: Message edited by: Lobo ]

  2. #2
    Lobo
    Guest

    Post

    TCP options string = 020405b40103030301010402

    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) = 474496
    RWIN Scaling (RFC1323) = 3 bits
    Unscaled Receive Window = 59312
    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: 18979.84 kbps (2372.48 KBytes/s) @ 200ms
    Your RcvWindow limits you to: 7591.936 kbps (948.992 KBytes/s) @ 500ms

    MTU Discovery (RFC1191) = ON

    Time to live left = 54 hops
    TTL value is ok.
    Note: Since TTL is decreased by at least 1 with each hop, the value above is equal to your TTL minus the number of hops to forums.speedguide.net

    Timestamps (RFC1323) = OFF

    Selective Acknowledgements (RFC2018) = ON

    IP type of service field (RFC1349)= 00000000
    Precedence (priority) = 000 (routine)
    Delay = 0 (normal delay)
    Throughput = 0 (normal throughput)
    Reliability = 0 (normal reliability)
    Cost = 0 (normal cost)


    7249 connections tested since 03-10-2001, 14:30 ET
    Analyzer

  3. #3
    mpd
    Guest

    Post

    Lobo,

    your data shows that the WIN value from the TCP header must be shifted left by a factor of three (the same as multiplying it by 8).

    Now, if your RWIN is 474496, your original WIN value must have been 59312.

    If the RWIN is 474500, then the WIN value must have been 59312.5. A rather strange value..

    What I am trying to say is that the only valid RWIN values are the ones divisible by 2^shift_factor.

    Mike.

  4. #4
    Super Good Guy! dannjr's Avatar
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    Post

    mpd
    Not nessassssarly but here read this on Rwin.. Real good thread... http://forums.speedguide.net/cgi-bin...c&f=2&t=007975

    Lobo
    How much Latency do you have... whats your average ping and average Download...
    What do you use with your connection
    These are all factors ????
    Two much Rwin can slow you down to...

  5. #5
    Lobo
    Guest

    Post

    No looking at results from pcpitstop (WOOT) Speed is fine for 8:00 at night, pings are good, de rest is a secret

  6. #6
    Administrator Philip's Avatar
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    Lightbulb

    Dannjr, Mike is right.

    There are only two values in TCP headers, an unscaled RWIN, and a scale factor... By definition you must have a whole unscaled number, multiplied by a scale factor that's a power of two.

    Lobo, pcpitstop reads the RWIN value directly from the registry, while our Analyzer actually inspects your TCP packets, hence the difference.

    [ 03-12-2001: Message edited by: Philip ]

  7. #7
    TCP/IP Dude rmrucker's Avatar
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    Long Beach, CA, USA
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    Post

    I must applaud SpeedGuide, Philip and Mike on this. The TCP Analyzer is CORRECTLY reporting what the actual Receive Window is.

    PC Pitstop is simply reporting back the exact number that YOU have entered into the registry as your "DefaultRcvWindow" -- these two are NOT necessarily the same thing.

    SpeedGuide now has the ONLY tool that CORRECTLY reports RWIN over 65535. Their reported RWIN is the ONLY one you can trust.

  8. #8
    Lobo
    Guest

    Post

    Ok, great work guys, thank you

  9. #9
    Super Good Guy! dannjr's Avatar
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    Post

    heheheheUHm never said right or wrong just gave another veiw on it
    Oh yeah asked a question too...

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