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WEB (Wireless Ethernet Bridge) vs WDS (Wireless Distribution System) for 3 routers

Discussion in 'Tomato Firmware' started by Kiwi8, Jun 2, 2008.

  1. Kiwi8

    Kiwi8 LI Guru Member

    Hello everyone!

    The purpose of this thread is just to update some results from my testing of the two modes using my 3 routers, making me opt to use WDS instead. It is also for my future reference, so please bear with me. :D

    During the test, each router has a wired connection to a PC for the bandwidth test. The application that I used was IPerf.

    Results coming in the next few posts. Kindly do not post in the meantime until all tests are posted.
     
  2. Kiwi8

    Kiwi8 LI Guru Member

    Test 1 : WEB (Wireless Ethernet Bridge)

    Configuration:
    Gateway router (Alpha) as AP.
    Router 1 (Beta) as WEB to Alpha.
    Router 2 (Charlie) as WEB to Alpha.

    Average results from PC on Alpha to PC on Beta:
    [ ID] Interval Transfer Bandwidth
    [1900] 0.0-20.0 sec 45.9 MBytes 19.2 Mbits/sec

    Average results from PC on Alpha to PC on Charlie:
    [ ID] Interval Transfer Bandwidth
    [1900] 0.0-20.0 sec 45.9 MBytes 19.3 Mbits/sec

    Average results from PC on Beta to PC on Charlie:
    [ ID] Interval Transfer Bandwidth
    [1900] 0.0-20.0 sec 20.8 MBytes 8.73 Mbits/sec

    Conclusion: There is a halving of bandwidth when transferring from a PC on Beta to a PC on Charlie because Beta and Charlie have to talk through the Alpha router.
     
  3. Kiwi8

    Kiwi8 LI Guru Member

    Test 2 : WDS (Wireless Distribution System)

    Configuration:
    Gateway router (Alpha) as AP+WDS to both Beta and Charlie.
    Router 1 (Beta) as WDS to both Alpha and Charlie.
    Router 2 (Charlie) as WDS to both Alpha and Beta.

    Average results from PC on Alpha to PC on Beta:
    [ ID] Interval Transfer Bandwidth
    [1900] 0.0-20.0 sec 44.9 MBytes 18.8 Mbits/sec

    Average results from PC on Alpha to PC on Charlie:
    [ ID] Interval Transfer Bandwidth
    [1900] 0.0-20.0 sec 44.6 MBytes 18.7 Mbits/sec

    Average results from PC on Beta to PC on Charlie:
    [ ID] Interval Transfer Bandwidth
    [1900] 0.0-20.0 sec 20.8 MBytes 8.72 Mbits/sec

    Conclusion: There is a halving of bandwidth when transferring from a PC on Beta to a PC on Charlie because Beta and Charlie have to talk through the Alpha router, because Spanning Tree Protocol is in effect and the Alpha router was made the root bridge.
     
  4. Kiwi8

    Kiwi8 LI Guru Member

    That's all for the test, thanks.
     
  5. Kiwi8

    Kiwi8 LI Guru Member

    Just wanna update on the results, which I had an error.

    It turns out that in a 3-router system, we cannot have 3 routers talking to each other as it would constitute a loop. This applies for the WDS too and hence Spanning Tree Protocol has to be enabled for WDS unless the connection is not made between one of the three links.

    But I think an advantage of maintaining all three links amongst the 3 routers, using STP, is that any router can be manually made the root bridge as desired.

    Ihe WEB case, this would not be possible as only the WAN router can serve as the root bridge. This is because when Wireless Ethernet Bridge mode is enabled on the router, the WAN side is disabled.

    So I have to say WDS is more flexible in that sense.
     
  6. dvaskelis

    dvaskelis Network Guru Member

    FYI, typically it's referred to as WET, short for Wireless EThernet, bridging a wireless network with an ethernet one with both on the same subnet.

    There's a good article on SmallNetBuilder (formerly Tom's Networking) called Wireless Bridging NTK that has a good overview on different wireless bridging techniques, including a page on WET-style bridging. They also did a follow-up article with an WDS-style bridging overview in How To: Setting up WDS Bridging/Repeating.
     
  7. jsmiddleton4

    jsmiddleton4 Network Guru Member

    Trying to follow you here kiwi. Why in your last test would you wds the 3rd router, Charlie, to itself?

    "Router 2 (Charlie) as WDS to both Beta and Charlie."

    Wouldn't it just wds to rotuer 1 Beta?

    Also this is one of the reasons why I'd like to see WET get some attention regarding reporting ip/mac's reporting accurately. This setup would be a good setup to see how WET worked and it maybe faster and easier once you get multiple routers.
     
  8. Kiwi8

    Kiwi8 LI Guru Member

    Thanks.
     
  9. Kiwi8

    Kiwi8 LI Guru Member

    Sorry, that was a wrong statement by me (the perils of copy and paste :biggrin: ). The right statement should be:
    Router 2 (Charlie) as WDS to both Alpha and Beta.
     

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