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My DSL modem dropped down by 2/3 of speed with my new Mobo

Posted: Wed Jan 08, 2003 11:37 pm
by Slave
Ok... 2 weeks ago, I bought myself a completely new PC... new Video card, new motherboard, etc...

YET I kept the same DSL modem I had on my previous PC... and since then, my internet speed has dropped down by 2/3... like, instead of downloading at 90k/sec... I'm now capped at 30k/sec.

I seemed to have tried EVERYTHING... yet nothing has worked.

I tried:

-Switching my DSL Modem from PCI slot to another
-Tweaking every possible ways to gain speed
-Re-formated my PC
-Updated Drivers
-I even blamed my Internet Service Provider

Yet, a friend of mine which helped me alot, told me that the only possible remain thing to check out, is to check out "stuff" in the BIOS about IRQs of my DSL Modem... I have no clue what she speaks of, and unfortunately, her knowledge doesn't go as far as that... well... here's exactly what she told me:

"I had the very same problem with my SB Audigy ..... depending on what slot it is in .. it uses different IRQ's ......I can only have the Audigy in slot 3 otherwise it gets a shared IRQ and while playing Games it locks up....

it sounds like you have the same problem your Modem is sharing a IRQ ( I think) It sounds like a Driver/IRQ/Bios/mobo/chipset/cpu settings prob to me... But this is where my knowledge comes to an end."

So... I'm left with no clue at all on what the problem actually is...

My DSL Modem is a DEAWOO INTERNAL DSL MODEM DW2020P ADSL

My old PC was a 550mhz, P3, 192RAM PC100, with WinXP

My current PC is a 1.7ghz, P4, 256RAM DDR266, with the very same WinXP

My current motherboard is the AOPEN AX4B-533

I sure hope anyone could help me since I'm pretty much left in the dark with my problem :(

Thanks in advance to those who'll answer me :)

-Slave

Posted: Wed Jan 08, 2003 11:39 pm
by mnosteele52
Please read here so that I can properly help you, if you do not read ALL of it and answer ALL 6 questions at the top I will not help you. :)

Posted: Wed Jan 08, 2003 11:52 pm
by Slave
1- cable nut downloaded
2- told you in my msg, DSL
3- My ISP is AEI the web site is http://www.AEI.CA and the advertise speed is: 1.2mb/sec
4-TCP properties for IP = xxxxxxxxxxxxxx(dsl-xxxxxx.aei.ca)
Browser/OS = Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
Note: Read the FAQ if the above is not your IP address.

TCP options string = 020405ac01010402

MTU = 1492
MTU is optimized for PPoE DSL broadband. If not, consider raising MTU to 1500 for optimal throughput.

MSS = 1452
Maximum useful data in each packet = 1452, which equals MSS.
MSS is optimized for PPPoE DSL broadband. If not, consider raising MTU to 1500 for maximum throughput.

Default Receive Window (RWIN) = 1452
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 1452
RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
511104 (MSS x 44 * scale factor of 8)
255552 (MSS x 44 * scale factor of 4)
127776 (MSS x 44 * scale factor of 2)
63888 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 58.08 kbps (7.26 KBytes/s) @ 200ms
Your RcvWindow limits you to: 23.232 kbps (2.904 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.

MTU Discovery (RFC1191) = ON

Time to live left = 101 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000
5-my actual speed test is between 28k/sec and 42k/sec
6-WinXP... without the SP1


Satisfied? :D

Posted: Thu Jan 09, 2003 10:16 am
by mnosteele52
OK great use the following settings in CableNut:

DefaultReceiveWindow = 153600
DefaultSendWindow = 16384
DisableAddressSharing = 1
InitialLargeBufferCount = 100
InitialMediumBufferCount = 240
InitialSmallBufferCount = 320
LargeBufferSize = 81920
MaxFastTransmit = 64000
MediumBufferSize = 15040
PriorityBoost = 0
SmallBufferSize = 1280
TransmitWorker = 32
FastSendDatagramThreshold = 1024
EnableFastRouteLookup = 1
EnablePMTUDiscovery = 1
IgnorePushBitsOnReceive = 0
GlobalMaxTcpWindowSize = 31944
MaxFreeTcbs = 8000
MaxHashTableSize = 16384
MaxNormLookupMemory = 5000000
SackOpts = 1
SynAttackProtect = 1
Tcp1323Opts = 0
TcpLogLevel = 1
TcpMaxDupAcks = 2
TcpMaxHalfOpen = 100
TcpMaxHalfRetried = 80
TcpRecvSegmentSize = 1452
TcpSendSegmentSize = 1452
TcpTimedWaitDelay = 30
TcpUseRFC1122UrgentPointer = 0
TcpWindowSize = 31944
MaxConnectionsPer1_0Server = 10
MaxConnectionsPerServer = 8
DefaultTTL = 64
DisableUserTOSSetting = 0
TcpMaxDataRetransmissions = 6
DefaultTOSValue = 92

VERY IMPORTANT TO DO THE FOLLOWING

1. Under your LAN connection - properties - general tab, uninstall all the protocols there that you do not need.

2. Open IE and select tools - internet options - connections - LAN settings, make sure NOTHING there is checked.

3. Make sure you have the latest drivers for your NIC from the manufacturer. Set your NIC duplex mode to 10mb half duplex for Cable, for DSL it is ISP dependent unless you are using a router, if so then set it to 100mb full duplex for both Cable & DSL (the instructions are in my Help & Tips link). If you are using a router make sure you have the latest firmware.

4. Clear your temporary internet files.

5. Power cycle your modem, unplug it for atleast 15 seconds.

6. Download and update then do a scan with SpyBot, anything checked in red is spyware and safe to remove.

7. Make sure you do the faster web page tweak in my Help & Tips link.

:D :cool:

Posted: Thu Jan 09, 2003 2:53 pm
by HuNtEr DrAgOn
Why was your RWIN set at 1492 Slave ???

That aint right by default you were playing with it !

Image

Posted: Thu Jan 09, 2003 3:45 pm
by Slave
Originally posted by HuNtEr DrAgOn
Why was your RWIN set at 1492 Slave ???

That aint right by default you were playing with it !

Image


I was told that, for DSL it is recomended to put it that way... frankly I didn't seen any differances...



And Thanks mnosteele52, I'll check it out tonight (I'm at the job now :) ) I'll get back to you after I tried it... Thanks!

Posted: Thu Jan 09, 2003 5:22 pm
by mnosteele52
1492 is the proper MTU for PPPoE DSL, your RWIN is most likely being read improperly by the TCP/IP Analyzer. :D ;)

Posted: Thu Jan 09, 2003 6:50 pm
by Slave
Ok I just tried everything you told me too with Cablenut and the parameters and everything... and unfortunately... it didnt work :(

I did a speed test, and only gave me 40k/sec of download...

:(