[MrTuffGuySeguin]

My problem is as follows. I have a large amount of .avi files and .mpeg files stored on a network share (60G of stored files). The network share is connected via a DLink DIR 628 802.11N router and a WUA 160 Dual Band N USB Adapter. I am using the 5 GHZ Channel and have an indicated speed of 270 MPS. My signal strength is excellent. When I play the .mpeg files using WMP, there are no problems at all. When I play the .avi files, they will play slow until the first pass through. If I do not close WMP, and replay the file, it will play fine from that point on. If I close WMP, and I reopen the file, the same problem occurs. If I connect the PC with the network share via a CAT5 cable, bypassing the router, the problem goes away. I have tried disabling Windows firewall and my antivirus with no effect. File permissions for READ ONLY have been disabled along with Indexing for the network drive. Any help would be appreciated.

PC 1 is AMD 2800 2 G Ram 7200 RPM IDE drive
PC 2 is AMD 3200 CPU 2 G Ram 7200 RPM SATA Drive
Windows Xp SP3 both machines

[TerryNet]

Any other traffic through the router?

Any other wireless devices connected?

Have you checked for wireless interference?

Any of the above can seriously slow the Wi-Fi throughput.

[MrTuffGuySeguin]

As part of my testing I isolated the router from WLAN, disconnected all other wireless devices running on the 2.4 GHZ band, and removed any cordless phones in the area. Results were the same. In addition, all encryption was disabled on the router.

[TerryNet]

I don't understand how you "isolated the router from WLAN" and still had something connected to it by Wi-Fi. Anyhow, in case of a router problem look for a firmware upgrade and then reset it to factory default settings and reconfigure.

If it were a computer I'd advise making sure you have the latest correct wireless driver, but I have no knowledge of your "network share" or how it uses a USB wireless adapter or how/if you can update a driver.

And, there's still the possibility of wireless interference.

[MrTuffGuySeguin]

Computer 1 is connected to the router through LAN port 1 on the DIR 628. There is no connection to the WLAN port back to my ISP's modem. I have done this for troubleshooting purposes. Computer 2 (with the network share) is connected wirelessly through the WUA 160 to the DIR 628. This is what I meant by isolated. Sorry for the confusion. Both devices have the latest firmware/drivers. I will try moving things around though to see if there is interference. The one confusing part in all of this is that the video only plays slow the first time through. If I let it play through, and then replay it, it runs correctly. It will continue to do this until I close WMP11, and reopen it. I have tried adjusting the buffer size in WMP to no avail. Thanks for your help so far.

[MrTuffGuySeguin]

Correction to my post. I have no connection to the WAN port back to my ISP's modem. What I am hoping to do by this is to isolate the problem to the 2 PC's in question.

[TerryNet]

OK, I didn't realize that there was a Computer 2 involved. What is the "network share," and how does in connect to Computer 2?

Does Computer 2 have USB 1.1 or 2.0? Anything else on USB on Computer 2?

[MrTuffGuySeguin]

The network share is on computer 2 and is a shared folder. The .avi files are stored in this shared folder. Computer 2 has the WUA 160 N adapter connected to a USB 2.0 connection. The other USB devices on Computer 2 are the transmitter/receiver for a wireless mouse and keyboard, and a USB webcam.

[TerryNet]

USB is less reliable for networking than PCI, PCMCIA or ExpressCard because of potential contention on the bus. My guess is that the webcam could be the source of your slow Wi-Fi; I suppose the mouse and keyboard could also be contributing, but less likely.

[MrTuffGuySeguin]

I have completed the following steps to see if the problem can be corrected:
1) moved router to within 0.3 metres of wireless adapter on computer 2
2) disconnected all USB devices except for the wireless USB adapter from computer 2
3) disabled alll WEP/WAP encryption
4) monitored traffic flow with Net Meter

Under these conditions there was no change. The one additional test I did was to monitor the traffic flow with a hard wired conncetion to transfer a 500MB file. With the hardwired connection my UL speed averaged 307.5 KPS. My DL was 8.0 MPS. With the wireless connection my DL average was 2.5 MPS and DL was 2.6 MPS. Seems like a large difference is traffic when using the wireless. Not sure if this helps, and any other suggestions would be appreciated. At this point I'm wondering if I need to switch out the router and network adapter. I would like to continue to use this netwrok adapter as I have not found a PCI card that works on the 5GHZ band. I have other wireless devices that are 802.11g running on the 2.4GHZ band. Those have been disabled during any of my testing.

[TerryNet]

I'll assume that Mega Per Second means Mega bits per second (Mbps).

You might try TCP Optimizer if computer 2 is using a Windows version earlier than Vista.

[MrTuffGuySeguin]

You are correct that the speed is in Mbps. I have tried TCP Optimizer using default, optimal, and custom settings. I have tried a MTU as low as 1480 and a rwin as low as 32579. There was change in the problem. Is there any settings you might recommend, or is this a very trial and error situation.

[TerryNet]

When I use TCP Optimizer I just go with the optimal settings, as I don't know enough to try to customize.

Did we talk about the wireless driver earlier? If not, check to see if you have the latest driver. And with that, I'm out of ideas and questions.

[MrTuffGuySeguin]

Thanks for your help. I have downloaded the latest drivers for the wireless adapter and the latest firmware for the router. I may install a 2.GHZ PCI card to totally rule out the USB adapter being the problem, and I will continue with adjusting settings in TCP Optimizer. Again, thanks for your help.

[TerryNet]

You're welcome, and please let us know when you uncover something.