File Transfer Corruption - Tweaks to Blame?

[Aesalon]

I used the TCPOptimizer program and set it to optimal settings on cable for my system on WinXP and rebooted. I'm using a Linksys router with a Netgear FA311 NIC. Everything is speedy except for the fact that my file transfers over AIM are all becoming corrupted, even when off of the router and on other NICs. For example, I send an MP3 to someone and when the transfer is done, AIM says the file sent doesn't match. The other person plays the MP3 but it's all skippy and poppy everywhere. ZIP and RAR files also fail CRC checks when sent through AIM. My webcam and how it uploads to my FTP, the image gets corrupted too. Any ideas as to what could cause this?

[Lobo]

Please click in my signature where it says Test tweak here, then:
At top where it says edit click and select, Select all,
Then go back to same edit button at top, click and select copy.
Come back to Speed Guide, same thread you were on, in post reply box, with cursor blinking at begining of box go to top, edit, click, select paste, click, this will put information in box. Please X out your IP address, Thank you.:)

[Aesalon]

SpeedGuide.net TCP/IP Analyzer
Note: Read the FAQ if the above is not your IP address.
Browser/OS = Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Q312461)

TCP options string = 020405b40103030201010402

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) = 256960
RWIN Scaling (RFC1323) = 2 bits
Unscaled Receive Window = 64240
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)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 10278.4 kbps (1284.8 KBytes/s) @ 200ms
Your RcvWindow limits you to: 4111.36 kbps (513.92 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 51 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

[Lobo]

Test looks fine, click on Cable Modem Tips in help thread below in sig:)

[Lobo]

Download AIM on top of where it is now, it will just overwrite, Optimizer is not the problem:)

[Aesalon]

The thing is, it's not only AIM. When I remove the tweaks, everything works fine. When they're on, half of the things that use file transfers end up sending corrupted files. Make sense?

[Lobo]

No, is your NIC card set to 10BaseT, needs to be:)

[Aesalon]

It's set to autosense which shouldn't be a concern. Should I specify?

[Lobo]

Yes 10BaseT, see help thread below for reason:)

[Aesalon]

What good will this do?

[Lobo]

A lot:

Cable Modems only: Duplex setting
It has been verified by experiment that certain auto-negotiating ethernet cards (both in PCs and in Macs), when connected to certain models of cable modem, sense the ethernet duplex setting incorrectly. Such a cable modem has ethernet hardware which is capable of operating only in half-duplex mode, at 10 Mbps, yet some auto-negotiating ethernet cards sense it as full-duplex. If an auto-negotiation card incorrectly starts operating in full-duplex mode, there can be collisions between ethernet packets being transmitted in both directions at the same time, leading to packet loss, and repeated re-transmissions. There is no visible evidence of this apart from poor performance. This problem can be avoided by manually configuring your ethernet card to be 10 Mbps half-duplex. No ill-effects will transpire from doing this, even when it is not necessary. The exact wording of the setting changes required varies from one manufacturer to another, so the instructions below are necessarily rather broadly defined.
To make this change under Win98/ME, follow these steps:

Open Control Panel.
Double-click Network.
From the scrollable list, select your Ethernet adapter (rather than any dial-up) with a green icon.
Click the button Properties.
Click the tab Advanced to bring it to the front:
In the Property box, the property name to be selected varies according to model of ethernet card. Examples are: Network Link Selection, Media

Type, Connection Type, Duplex Mode, or any similarly-named property which can have Values looking like Auto-Negotiation, or 10BT, or

10BaseT.
In the Value box, select a value which either (a) explicitly says half-duplex or semi-duplex, or (b) at least does not say full-duplex [e.g. 10BaseT on its own is OK]. If there is a choice between 10 and 100 with half-duplex, choose the 10. Do not choose 10Base5, 10Base2, or AUI.
Click OK to exit the Adapter settings.
Click OK all the way out - you might need to restart.
To make this change under Windows 2000 or XP, follow these steps:
Open Control Panel.
Double-click Network and Dial-up Connections.
Identify the icon for your cable modem connection: usually Local Area Connection.
Right-click that icon and select Properties.
Under the ethernet adapter icon, click the button Configure.
Click the tab Advanced to bring it to the front:
In the Property box, the property name to be selected varies according to model of ethernet card. Examples are: Network Link Selection, Media Type, Connection Type, Duplex Mode, or any similarly-named property which can have Values looking like Auto-Negotiation, or 10BT, or 10BaseT.
In the Value box, select a value which either (a) explicitly says half-duplex or semi-duplex, or (b) at least does not say full-duplex [e.g. 10BaseT on its own is OK]. If there is a choice between 10 and 100 with half-duplex, choose the 10. Do not choose 10Base5, 10Base2, or AUI.
Click OK to exit the Adapter settings.
Click OK to exit the Connection properties :)

[Aesalon]

Would it make a difference since I'm behind a router?

[Lobo]

Do it, it does not hurt:

If an auto-negotiation card incorrectly starts operating in full-duplex mode, there can be collisions between ethernet packets being transmitted in both directions at the same time, leading to packet loss, and repeated re-transmissions:)

[mnosteele52]

I don't think the tweaks are corrupting your transfers, I never have a problem with direct tranfers and my pc is tweaked. Just to see, drop your RWIN to 64240 and see what happens.:) ;)

[Aesalon]

10BaseT half-duplex it is.

My concern is that when I remove the tweaks, it fixes the problem. So I'm wondering which specific tweak causes this problem.

[Lobo]

Have you been messing in services folder:)



Or check that security or firewall settings are not to high, maybe help in Computer Security Forum :)

[Aesalon]

Might've...

[Travlin_Man]

Maybe way off base here,, but with his rwin at high level,,, has he unchecked win scaling or checked timestamps??

[Lobo]

If you been in Services, thats where it's at, the problem, I don't mess with that folder:) :)

[Aesalon]

Originally posted by Travlin_Man
Maybe way off base here,, but with his rwin at high level,,, has he unchecked win scaling or checked timestamps??

Travlin_Man,

I followed the suggested settings in the TCPOptimizer program so WinScaling is checked and Timestamps are unchecked.

[mnosteele52]

Look here (http://www.3dspotlight.com/tweaks/winxp_services/index.shtml) for tweaking your services.:) ;)

[Aesalon]

I remember looking through the services but never modifying any. I'll go through and check.

[Lobo]

The ONLY reason to mess with services is if you have very little RAM and know what you are doing

[Aesalon]

With no doubt. I'll give the 10BaseT half-duplex thing a try and report back.