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B/G Identification

Discussion in 'Tomato Firmware' started by Toastman, Jul 24, 2008.

  1. Toastman

    Toastman Super Moderator Staff Member Member

    I want to check users on my network to see who is using old "B" wireless hardware. Anybody know if there is a way to find out this information in Tomato 1.19 / 1.20 ?

    Thanks!
     
  2. TexasFlood

    TexasFlood Network Guru Member

    Set your routers to 802.11g only and see who screams? :biggrin:
     
  3. Toastman

    Toastman Super Moderator Staff Member Member

    I did, got my teeth knocked out. That's why I want to know. If there aren't many, I want to switch B off to keep speed high on those AP's.

    Off to the dentist...
     
  4. TexasFlood

    TexasFlood Network Guru Member

    OK, seriously...

    You can do a "wl autho_sta_list" command to get a list of MAC addresses of authorized wireless devices associated with the router you run the command on. Then you can do a "wl sta_info xx:xx:xx:xx:xx:xx" command on an individual MAC from the output of the above command. 802.11b should only show rates of 1, 2, 5.5, & 11. If you other rates, like 18, 24, 36, 48, & 54 that should indicate an 802.11g connection. You could write a script to gather this info at defined intervals. It would be pretty simple just to gather the data but could get fancy if you wanted to have the script massage the data for you.
     
  5. dvaskelis

    dvaskelis Network Guru Member

    You may wish to experiment, but a couple years ago in my highrise I did some testing of G-Only vs. Mixed mode.

    In my environment with only 802.11g devices, I got better speeds in Mixed mode over G-Only mode. Sometimes, much better, as in 20% faster.

    At the time, I posted on the HyperWRT forum and someone pointed out that in G-Only mode, that any signals even similar to 802.11b will be treated as interference and interrupt 802.11g transmissions. I don't know if that's true, but it sounds good. :)
     
  6. Toastman

    Toastman Super Moderator Staff Member Member

    Thanks both for your comments. I'll try that now Tex..

    I heard that the bandwidth of a G transmission is a little narrower than B, and the sidebands weaker at the extremities. This would allow the use of 4 channels without interference, and in practice, it seems to be true. Last week I took a router to a local factory where they have some decent test gear. I had a look at the sideband splatter using a spectrum analyser, and, while not being expert at interpreting the results, it did appear to be narrower when using G - B clearly had more energy at the edges.

    I use 1,5,9,and 13 alternating around the buildings.

    I would expect that if B were switched off, and the router thus didn't try to decode it, it would be treated as noise. But then, since it got no reply, it would hopefully shut off quickly. At any rate it would be better than slowing down all the other traffic.
     
  7. Toastman

    Toastman Super Moderator Staff Member Member

    Yep, it works. Thanks Tex.
     
  8. TexasFlood

    TexasFlood Network Guru Member

    Great. Actually on second look, you probably want the "wl assoclist" command rather than the "wl autho_sta_list". That should get you just the accociated clients leaving off WDS linked devices.
     
  9. Toastman

    Toastman Super Moderator Staff Member Member

    OK, ta
     

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