Wireless router slows connection
in [Wireless Internet]
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From: Jeff Liebermann on 2 Apr 2007 18:08 On Mon, 2 Apr 2007 13:03:10 -0500, "Jim" <jcgc50(a)cox.net> wrote: >Jeff, sorry, I sent this response to you rather than the group. Will try >again. Not a problem. I've been ignoring my email for weeks. It's amazing how much more spare time I now have. >I am using a laptop which happens to be located in the same room. Signal >strength shows excellent at 54 mbps. Many unspecified laptops and random wireless cards report 54Mbits/sec on initial connection and when there is no traffic. Try downloading something and see if the wireless connection speed changes. Also, I kinda perfer to have the numbers instead of generalizations such as "excellent". What number did you get for signal strength (in -dBm) and what does it show for SNR (signal to noise ratio). Get these numbers while moving data or immediately after a download. It's possible to have excellent signal strength, but rotten SNR due to interference. >I have been using this setup for over a >year now and it has always been this way and I have not figured it out. I would have guessed interference but there are few forms of interference that last for "over a year". Also, if it's in the same room, the likelyhood of substantial interference having an effect is considerably less. Obviously, it's also not signal strength. >SSID >broadcasting is turned off and I have MAC filtering. Both are a lousy idea. SSID hiding just means that your neighbors will end up on your chosen channel. MAC filtering has it's place but is easily spoofed. However, you did mention that you're using WPA encryption, which is really your main and only form of security. Hopefully, you've selected a long and difficult to brute force guess pass phrase. >I have changed those >settings and found no difference in performance. Question: Was the wireless performance good at any time in the past year? >If it didn't involve too much work I would arrange to run this wired most of >the time. As it is I am only occasionally downloading large files. > >WRT54G v 3.1 Firmware 4.20.7. I have upgraded the firmware once and don't >know if there is an update but that did nothing either. The current version of the firmware is 4.21.1 issued Jan 20, 2007. You might want to try it. >Does this information provide any ideas. Not really, You've adequately described the WRT54G end of the link. However, the other end is still a mystery. It takes two to tango and the problem could easily be in the wireless part of the laptop. Any particular maker and model number? Any particular wireless device? Extra points for finding the firmware version. Since you get adequate speed with a directly wired ethernet connection, it's probably not a worm or virus hogging CPU cycles in the laptop. It might be some configuration issue involving the wireless device, but that's very rare (unless you've been tinkering in the wireless devices properties). It might be traffic from a neighbor leaching off your wireless, but that would not be continuous for the last year. One way to really screw things up is to have two systems using the same SSID. For a quick test, change your SSID to something else that's sufficiently obscure not to be duplicated. You might also try different channels (1, 6, or 11) and see if that helps. It probably won't but it's easy enough to try. You only need to change the channel in the WRT54G as the client radios will follow the change. The way I would troubleshoot this one is by substitution. Find a different known working laptop and try it to see if it has the same problem. If that results in the same lousy wireless performance, then there's either interference of some unknown type, or the WRT54G has a problem. At some point, you might want to scribble down all the WRT54G settings, update the firmware, reset the router to defaults, and put them back manually (not from the saved image file). Just put back enough setting to be able to use the system and never mind the security details and tweaks. Basically, try it with the default settings. If that works, then one of the setting broke something. I had one user do this only to find that someone had inadvertently set the wireless to 802.11b only, which limited the wireless speed to about 5Mbits/sec. Setting such as CTS/RTS flow, 802.11b compatibility, fragmentation threshold, etc will cause slowdowns. The next step is to replace the router with a different model. It might be possible to borrow one. If that works as expected, then there's something broken in the router. It's probably too late for a warranty claim. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 jeffl(a)comix.santa-cruz.ca.us # http://802.11junk.com jeffl(a)cruzio.com # http://www.LearnByDestroying.com AE6KS |