Subject: Re: OSA/Express - This Doesn't Make Any Sense!
From: David Stuart (David.Stuart@ventura.org)
Date: Mon Aug 18 2008 - 16:29:00 EDT
Afternoon All, Ok, it appears to be fixed. To recap, the actions taken were to 'hard code' the OSA/Express ports to 100 mbps full-duplex (instead of letting it auto-negotiate), and adding the Win/XP Registry Key value TcpAckFrequency and setting it to 1. Between the two, I now download as fast as I upload. A recent test hit a peak of 4.1MBps/second. Thanks to all who had suggestions, and Jeff and Mike for pointing me to TcpAckFrequency. Thanks, Dave Dave Stuart Prin. Info. Systems Support Analyst County of Ventura, CA 805-662-6731 David.Stuart@ventura.org >>> "David Stuart" <David.Stuart@ventura.org> 8/18/2008 9:33 AM >>> Hi Jeff, I'm working on it. I found the MS article that Mike Moore pointed me to. I have added the registry values. Next, I think I need to reboot. I should be able to do some testing later this morning. Dave Dave Stuart Prin. Info. Systems Support Analyst County of Ventura, CA 805-662-6731 David.Stuart@ventura.org >>> "Jeffrey Barnard" <bsiopti@bsiopti.com> 8/18/2008 9:05 AM >>> David, I think you will find that adding a registry entry for TcpAckFrequency Full_Dword = 1 will disable the Windows ACK delay and fix your problem. I was able to re-create the issue here on a Windows XP SP3 box and this fixed the problem. Verify you have the require hotfix applied too (if needed, SP3 already has it applied). FWIW, My Linux systems do not have this problem and have higher transfer rates too. Regards, Jeff -- Jeffrey C Barnard Barnard Software, Inc. http://www.bsiopti.com BSI 407-323-4773 Support 407-688-7123
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