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Standard User flycop2000
(newbie) Tue 20-Jun-06 16:33:05
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Modem setup values?


[link to this post]
 
Hi,
I have a Zoom X3 ethernet modem connected to USRobotics 8000 Router. I am using win XP Media centre 2005 operating system. I have used Dr TCP to test my setup and made the recommended adjustments to the MTU.(recommend 1500) I then went into my modem and set the MTU to 1500., MCU 1500, I never changed the MSS. What exactly are these values? My previous values were MTU 1492, MCU 1492, MSS 1432. I never noticed any difference to my stats. Should they make much difference to my line states? I have already spoken to BT about my slow connection and they agreed that I have a lot of noise on my Line and will call me in a few days for an update. (attenuation 54.5 down stream, SNR 6.8, CRC errors 419 in 160mins, data rate 4256.
any help would be appreciated.

Richard.
Standard User yarwell
(legend) Tue 20-Jun-06 16:53:39
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Re: Modem setup values?


[re: flycop2000] [link to this post]
 
definition of MSS etc

Phil

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Edited by yarwell (Tue 20-Jun-06 16:54:32)

Standard User flycop2000
(newbie) Tue 20-Jun-06 17:01:36
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Re: Modem setup values?


[re: yarwell] [link to this post]
 
Hi Phil,
Thanks for the quick response, unfortunatly the link states the page has moved or unavailable.

Richard.


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Standard User Malki
(member) Tue 20-Jun-06 17:07:04
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Re: Modem setup values?


[re: flycop2000] [link to this post]
 
Loaded ok (slowly) for me so i copied the text for you

In reply to:


The maximum segment size (MSS) is the largest amount of data, specified in bytes, that a computer or communications device can handle in a single, unfragmented piece. For optimum communications, the number of bytes in the data segment and the header must add up to less than the number of bytes in the maximum transmission unit (MTU).
The MSS is an important consideration in Internet connections, particularly Web browsing. When the Internet's Transmission Control Protocol (TCP) is used to achieve an Internet connection, the computers being connected must each agree on, and then set, the MTU size acceptable to both. Typical MTU size in TCP for a home computer Internet connection is either 576 or 1500 bytes. Headers are 40 bytes long; the MSS is equal to the difference, either 536 or 1460 bytes. In some instances the MTU size is less than 576 bytes, and the data segments must therefore be smaller than 536 bytes.

As data is routed over the Internet, it must pass through multiple gateway routers. Ideally, each data segment can pass through every router without being fragmented. If the data segment size is too large for any of the routers through which the data passes, the oversize segment(s) are fragmented. This slows down the connection speed as seen by the computer user. In some cases the slowdown is dramatic. The likelihood of such fragmentation can be minimized by keeping the MSS as small as reasonably possible. For most computer users, the MSS is set automatically by the operating system.







X2 3800 Toledo @ 2.6 1:1 / 2Gb Corsair 3500LL Pro @ 260Mhz 3-3-2-6 1T / 7800GT Vmod @ 491/1180

SpeedTouch 585 v5
ZeN Home 2000

Edited by Malki (Tue 20-Jun-06 17:07:57)

Standard User yarwell
(legend) Tue 20-Jun-06 17:26:03
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Re: Modem setup values?


[re: flycop2000] [link to this post]
 
your slow connection I'm afraid.

attenuation 54.5 down stream, SNR 6.8, CRC errors 419 in 160mins, data rate 4256.

not bad, a 3.5M BRAS profile connection well outside the range of BT's fixed speed 2M service.

So what speed test results are you getting ? also what's your RWIN value ?

Phil

MaxDSL user survey - results back online.

MaxDSL speeds - what do they all mean.
Standard User flycop2000
(newbie) Tue 20-Jun-06 20:31:01
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Re: Modem setup values?


[re: yarwell] [link to this post]
 
Hi Phil,

My stats for 3hrs 27 mins
SNR: 5.8 / 22.0
Atten: 53.2 / 30.0
Error secs: 694 / 22
loss of sig: 0 / 0
loss of frame: 0 / 0
CRC error: 798 / 38
Data:4320 / 448
latency: fast / fast


Standard User flycop2000
(newbie) Tue 20-Jun-06 20:37:59
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Re: Modem setup values?


[re: flycop2000] [link to this post]
 
Forgot result of tests. Morning / afternoon / evening

Monday. 2.8mb / 2.8mb / 1.4mb
Tues 1.8mb / 1.8mb / 1.5mb

can you remind me how to find my RWIN value again!
Standard User yarwell
(legend) Tue 20-Jun-06 23:39:00
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Re: Modem setup values?


[re: flycop2000] [link to this post]
 
RWIN etc - http://www.netmonitor.org/tools/ttest.php

DrTCP.exe to change it.

Speeds not too bad Monday, I would say consistent with a 3.5M service profile. Tuesday looks more like a 2M profile. Evening congestion in both cases ?

Phil

MaxDSL user survey - results back online.

MaxDSL speeds - what do they all mean.
Standard User flycop2000
(newbie) Wed 21-Jun-06 08:52:12
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Re: Modem setup values?


[re: yarwell] [link to this post]
 
Thanks for the help. I tried the www.speedtest.bbmax.co.uk test this morning and recorded 3.3mb download, the highest reading so far.

Richard
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