Wifi low speed with Tomato

Discussion in 'Tomato Firmware' started by awer1967, Jul 29, 2012.

  1. awer1967

    awer1967 Addicted to LI Member

    Good day ,dear All !

    Please, help me .

    I have notebook with embedded Wifi -N adapter Atheros AR9285 (with last native drivers from Atheros). It connect to Inet through the my WRT320N . When it flash with native CISCO software speed WiFi connection is 150 Mb/sec, but on Tomato it falls to 72,2 Mbit/sec. I read a lot of forum messages and dig the packets and could not found WHY IT SHIT HAPPENS.

    The setttings on linksys OEM software and Tomato are the same .

    What did I to resolve that issue ?

    1. I was change number of channels (from 1 to 11), set router to the N-mode only (very inappropriate for me), try to use 20 and 40 GHz Channel width..
    2. I was play with many setting on the advanced wireless page - with transmit power (from 100 to 300 mW) and many others..No luck anymore

    I see ,when wifi settings changed on the router and notebook adapter stay disonnected it speed immediately increase to 150 mb/sec . But if it connect to router - connection speed degrade to 72.2 Mb/sec at the moment.

    I don"t understand nothing.
    Please, help me.
  2. Mangix

    Mangix Networkin' Nut Member

    have you actually benchmarked lower performance e.g. with iperf? What you're seeing is probably a visual anomaly where the stock firmware is showing you the current setting whereas tomato is showing you the actual speed.

    Another possibility is that you need to enable 40MHz channel width. That's probably it actually.

    A small note on transmit power: high is actually bad, especially with internal antennas. Higher power causes more noise to be transmitted compared to signal.. It's all about having a high SNR ratio and high ones are achieved with low transmit power.
  3. awer1967

    awer1967 Addicted to LI Member

    Yes I did some tests speed of wifi link . All of them was detect that speed degraded when I use Tomato on the WRT320N. This is not a visual effect.

    I was try to do this but with no luck. I used many of combination settings with different channels and 20 or 40 mHz width . Nothings of results.

    Yes I know it . I set maximum transmit power to the 150 mW - no more , because of big noise.

    Any ideas now, really.
  4. Mangix

    Mangix Networkin' Nut Member

    this is very strange. when you set the channel width to 40MHz, let's say channel 5, channel 3 or 7 is used as an extension channel. The extension channel should not have anything to do with the main channel.

    The only two possibilities I can think of is either you have the channel width setting at Auto or it's bad firmware. What version are you running?

    It could also be bad hardware but I have my doubts. Or you're setting the 40MHz setting for the 5GHz only...dunno.
  5. awer1967

    awer1967 Addicted to LI Member

    Thanks Mangix ! I use 40 MHz and channel 10 because all lower channels are busy .

    Now I use now Shibby release (097 version) . Before I used pure TomatoUSB. The same result in both cases.
    And not only notebook connect at 72 Mb. The same are with my SE Xperia :(

    I could not set 5 Ghz because of two Kindles wifi and wife notebook with b/g adapter.:( BTW they all connected on 54 GHz ....
  6. awer1967

    awer1967 Addicted to LI Member

    Now I change firmware with Toastman release
    The same result
  7. Mangix

    Mangix Networkin' Nut Member

    Don't know what to tell you then. It's probably just a visual anomaly with the stock firmware displaying the setting vs. the actual.

    And the 54mbps thing makes sense. WiFi is only as fast as the slowest device. So if you have a b device and an n device connected at the same time, it's 11mbps on both of them. Only possible thing to do is disconnect the b device. Or have two antennas, one doing N only and the other B/G.
  8. awer1967

    awer1967 Addicted to LI Member

    In addition I forget to say that AR9285 works on the 2.4GHz frequency only ,not on 5 :(

    It is really dumb situation

    I cannot stay on the stock firmware because of IPTV (but it takes 150 Mb),
    and my lovely Tomato cut the wifi speed

    Anymore , thanks for a help
  9. awer1967

    awer1967 Addicted to LI Member

    I find reasonable suggestion on the HP forum


    From what I have read on other forums, it appears that channel 40 Mhz(needed to reach 150 Mbps) cannot be used when other wireless networks are detected by router. This doesn't happen in all cases, only when channels 1,6,11 are occupied, or when one network 802.11g is detected. (Not sure about the exact conditions but I suppose that are like these enumerated). So, in my case the router and the notebook wireless adapter are OK, and the limitation to 72mbps is caused by the bad design of the 802.11n protocol

    Today at morning I checked again my situation - I was try to connect with my WRT320N by the neighbour's notebook with Broadcom Wifi N adapter. The same situation.
  10. awer1967

    awer1967 Addicted to LI Member

    Wow. another sad message from Cisco

    The problem is the E2000 isn't channel bonding. The router needs to be channel bonding to combine two 20mhz channels which gives you a higher data rate (150mbps).

    This router uses MCS index 7, so that tells you why it is choosing 72mbps. It also seems that your adaptersare in a 1x1:1 (1 receive antenna, 1 transmit antenna, and 1 send/receive spatial stream) antenna configuration so they won't go any higher than 150mbps.

    Usually interference from other networks is the issue. I think the problem is what the router considers to be tolerable/intolerable interference. It seems that Netgear routers are more tolerant of interference.

    So if you have already set the E2000 to auto 20/40 mhz channel width and it still isn't bonding, then there really isn't anything that you can do. You could call Cisco and tell them that the Netgear channels bonds, but the E200 doesn't.

    But native software can do 150 Mb ......May be it is some soft feature ???
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