Wireless Driver Issues & Settings for N speeds

Discussion in 'Tomato Firmware' started by Toastman, Sep 24, 2011.

  1. Cumulonimbus

    Cumulonimbus Networkin' Nut Member


    have you configured your two E4200 als Client Wireless Bridge or via WDS?

    I have configured mine E4200 as Client Wireless Brigge. WDS won't work. :-( Don't kniw why.

    Without Secure Encryption, i have receiced 280-300Mbit over a distance over 12 meters with 1 door. With WPA2-Personal AES, i have a bandwidth over WLAN from 250-265Mbit.

    I have spend some hours to Test for best Settings, so i have found out, the use of the right Channel is also important as set the right TX-Power. Best Channels on my 5GHz-Enviroment are 112 to 120. You can this set, if you chance your local to Belgium. Also set the TX-Power to 60-65. Over 65mw, the Performance not dramaticaly better.

    Interesting: If i set loweder Channels 36 to 48, Performance only 160-180Mbit. Same if i set the Channeles in upper Band from 136-161. So the middle Band in 5GHz-Band are. Try it. It can help to boost your Performance.
  2. Cumulonimbus

    Cumulonimbus Networkin' Nut Member


    Used Firmware: Tomato Firmware v1.28.0494 MIPSR2-Toastman-VLAN-RT-N K26 USB Ext

    Configuration: 2x E4200. 1 E4200 as Accesspoint, 1 E4200 connected to Accesspoint via Client Wireless Bridge
    Accesspoint is configured with 5Ghz only. QOS enabled, Bandwidth-Limiter enabled.

    If one Device the LAN is connecting and this Device are an Entry in Bandwidth-Limiter, the Access Point reboots exactly one time. After this reboot, the Accesspoint works well.
  3. Noxolos

    Noxolos LI Guru Member

    Thx for the replies.
    I had this configuration up running for months with two WRT54GLs and Tomato.
    WDS was never a real solution for me because it doesn't support WPA2 and it is more fault-prone than the Wireless Ethernet Bridge.
    A really good working WDS solution with WPA2 and a "backbone" based on the 5GHz radio would be a nice dream for the future ;)
    I won't use the Bandwith-Limiter and QOS so I hope there will not be a reboot problem. But thanks for your advice.

    I'm not sure about the channel selection. I've read that you will get the best performance on 5GHz with channel 161:
    "Highest transfer rates are being achieved on Upper channel 161"
    Source: http://www.dd-wrt.com/wiki/index.php/Linksys_E4200#5GHz_Wireless_Transfer_Speed_Tips
    I will have to try different channel settings.

    An interesting point I've noticed:
    With region set to USA and TX-Power set to 0 (=hardware default) on the 2,4GHz radio I seem to achieve a slightly higher power level.
    I have to investigate this issue thoroughly.

    What about the Cisco LED, is there a chance to disable the LED with a telnet command?
    Is the 30-30-30 reset recommended to flash from Linksys stock firmware to Tomato or does clearing the NVRAM after flashing to Tomato do the job?
    If I got you right, clearing the NVRAM is enough, correct?
  4. Cumulonimbus

    Cumulonimbus Networkin' Nut Member

    Yes, before i start my own Test-Session, i use Tipps from this Site too. But result of my tests are saying other thinks. Other Conditions ins your Envirement need other Settings i think.
  5. Noxolos

    Noxolos LI Guru Member

    Does anybody know a good and easy tool to measure wireless throughput in a Microsoft Windows environment?
  6. ntest7

    ntest7 Network Guru Member

    The free Ixia QCheck tool works fairly well for this. You install "endpoints" on your computers and routers (they have a OpenWRT mips version that works on tomato, a linux version, and various windows versions) and then use the QCheck control tool on a windows box to initiate the test between any two devices on your network.


    Other test tools are described here:
  7. Oleg Repin

    Oleg Repin Networkin' Nut Member

    Hello, Jacques. I have found a solution how to drastically increase USB speed. You could look at the thread: http://www.linksysinfo.org/index.php?threads/usb-speed-up.36731/
  8. LanceMoreland

    LanceMoreland Network Guru Member

    Channels in the 112 to 120 range are not available to me in the drop down menu.

    Edit: Nevermind, set to Belgium for those channels. I need to learn to read.
  9. Toastman

    Toastman Super Moderator Staff Member Member

    Maybe this would also be helpful information for many people.

    The 5GHz band is often assumed to be interference-free and a magic cure-all to our problems on 2.4GHz.

    Not so. The band also has its own problems.

    There are 23 channels used in the US but often only 8 are supported in OEM routers. There's a reason for that. 15 channels are for shared use with the military and the router firmwares are supposed to have routines built in that detect such military use and avoid those channels. The chances of this happening are relatively low, but still it might happen, so manufacturers sometimes avoid using them altogether. Quite probably because they know their software kludge isn't gonna help the situation much.

    Let's look at those 8 channels that are left.
    Those eight widely used channels, however, are split into two pieces: a lower band, called UNII-1 for the lowest band of the Unlicensed National Information Infrastructure range, and an upper band, UNII-3. The 15 other channels are in the UNII-2 range, split between what's generally called the lower UNII-2, which has four channels, and the upper UNII-2, which has 11 channels.
    The lower four channels are numbered sequentially as 36, 40, 44, and 48. The upper four channels are likewise numbered as 149, 153, 157, and 161. (The reason for the four-unit gaps is that the channels are 20 MHz wide, but channel numbers are assigned in 5 MHz increments.)
    The lower band uses 1/20th the power of the upper band. That's right: Choose channel 149, and your base station broadcasts signals at 20 times the power of channel 36! (The 5 GHz band, because of its shorter wavelength, requires more power to send the same quantity of data the same distance as a 2.4 GHz device.)
    There's a second problem with the upper band: it's used for 5 GHz cordless DECT phones. These phones use an entirely different technology that can disrupt Wi-Fi performance without violating any FCC rules.
    Finally, if you use so-called wide channels, which use 40 MHz of bandwidth to double 802.11n throughput, you're down to just four possible channels (36 or 44 in the lower band, or 149 or 157 in the upper band).
    ( full article is at http://tidbits.com/article/10849)

    If the low power use in the lower band is really implemented in the wireless drivers, then best avoid that band unless you need short range only. The upper band is subject to DECT phone interference.
  10. Cumulonimbus

    Cumulonimbus Networkin' Nut Member

    Hi, need help, but i am not sure if its the right Forum.

    How can i Chance the MAC-Adresse of WAN via Shell?
  11. eahm

    eahm LI Guru Member

  12. Toastman

    Toastman Super Moderator Staff Member Member


    The RT-N wireless driver(s) is somewhat experimental in nature. It is intended for use with the Linksys E4200, the ASUS RT-N10/12/66 models. The driver is large and takes up a lot of room, so it's not very useful for earlier routers. Experience also tells us that for the majority of users, it has been rather slow and buggy. However, at least one person has had good results using it on an RT-N16.

    My recommendation for the RT-N16 is to use the normal (STD) RT version. If you try the RT-N version and have problems with it, please don't post complaints in the forums, as you aren't recommended to use it in the first place. And there's nothing we can do about anyway.


    We are trying to use one wireless driver for a multitude of different routers. That has always worked in the past when the drivers were relatively simple. We tried several drivers from different manufacturers and by trial and error found one that seemed to work with the majority of routers. As you will all know, there have always been various problems with encryption, WDS, and so on, from time to time.

    Now the situation has got much worse.

    We now have many new routers on the market using wireless N. That necessitates rather complex wireless drivers. Each manufacturer commissions Broadcom to come up with a wireless driver for their own hardware model. Each model will often/usually have either a different driver or different configuration and support files! There are many, many different driver versions used in the various models around these days. They are in the form of precompiled modules and we have no source code, (Broadcom will not release code to the community) and even if we did have it, without the knowledge of how each function worked and what parameters it used, the code wouldn't be of much use to us. There are also hundreds, perhaps thousands, of changes in other files for some of the drivers. Some drivers have additional NEW support files (by which I mean any file using or related to the wireless driver) and others deleted. We have very little idea what those changes mean.

    Now, we may see the same "version" wireless driver used on different routers. Fine. But we don't know if or how many parameters have been "tuned" in that driver for a particular model by a particular manufacturer. Just one wrongly set parameter may be all it needs to wreck the wireless performance, cause dropouts or reboots.

    Do you see the problem?

    Last year, for example, Teddy Bear changed the wireless driver for the RT builds from to He found it worked better with certain Belkin models. However, he never released a version for others to test, so we ended up with that task. But tests over several months proved that it was responsible for a lot of rather obscure and hard to pin down problems on many more common router models. The driver was clearly not suitable for hardware other than that which it was designed for.

    I therefore reverted my builds to and the results have been better. I have no idea what router Teddy took this driver from, if you want to know, you must trawl through the thousands of posts on the TomatoUSB and Linksysinfo forums.

    The RT-N driver was used in a separate branch for the E4200. Now we've added a few more routers to that branch. We don't know where this driver came from, what router(s) it and its support files were intended for. There are more settings even then previous drivers, and maybe some of them are not correct, or are correct only for some model(s).​

    There are even more complex drivers coming out now, and for the most part, they are bulky and don't work so well on older models. They are also exceedingly difficult to incorporate into Tomato - which is why there's nobody working on this at the moment. We really do need someone with expert knowledge of these drivers and how to use them, but sadly, we aren't likely to get anyone with that knowledge to do it. In fact probably the only people with the required knowledge work for Broadcom.

    So support for newer models is usually limited to the existing drivers (RT and N) from Teddy Bear. Which may have (mostly) worked for (most of) the functions on (most of) the models that were around a year ago but won't do so much longer.

    You should therefore be beginning to see the problems - we have cobbled together a few (kind-of) working wireless driver(s) into Tomato, but they may support a particular model well, others less so, and may be unstable with yet another.

    The fact is - we don't have any "One Fit For All" solution. It almost certainly doesn't exist. Even the original manufacturers often had unsolved bugs, which we inherited.​

    In future, some models are probably going to need very special builds.

  13. Dent

    Dent Network Guru Member


    So Toastman, for the current RT-N wireless drivers that you are using, which specific hardware model were these actually designed for? The E4200?
  14. Noxolos

    Noxolos LI Guru Member

    Has anybody officially asked Broadcom about the driver?
    Maybe they would support the community that helped to make Broadcom based routers so popular?
  15. CardinS2U

    CardinS2U Network Guru Member

    Infact this is rather interesting. I am using WNR3500L with your latest built in. I tested the last 3 builds and wireless performace is the same. If I connect to LAN then speedtest.net is always in the 22mb (my line speed)

    but if I connect to Wireless and do speed test..it never surpass 10mbs. Most of the time it goes around 6-8mbs even though the link/connection health is full bar and connected at 124-300MB

    this brings up the question: is your RT-N16 that you speak of over the years since I last spoke with you is stable ? If so I might have to buy that router and use it because I need the wireless performance.

    If I get that router would I get the horrible wireless performance I'm getting with WNR3500L .....I know its the broadcom driver for sure but hope this isn't on RT-N16 since its a waste of money if I buy it. =)

    Secondly is there a way that you can create a .config export/import for QOS classification that we set. I don't mind setting other things when we do a clean install. But its hell to re-enter all the QOS for netflix and other services (xbox live gaming, etc)

    Cardin Nguyen
  16. Toastman

    Toastman Super Moderator Staff Member Member

    Cardin, please read this post about backing up settings:


    This and answers to many other common questions are in the link in my signature, common tomato topics. Here it is again:


    The whole gist of the above post is to make people aware that there is no magic solution to the various wireless driver problems, and why. And to point out that even the major manufacturers actually suffer from the same problems themselves.

    I find the RT-N16 extremely stable. It can handle the 16Mbps speeds I use it at over wireless. I never have any problems with it at all on my test system. The E3000 also never gave me a problem. I don't use WDS or WEB etc. Yet that is not the case for everyone with an RT-N16. I can't "promise" it will be better.

    In fact apart from one RT-N16 for personal "test" use, none of my mission critical routers run wireless. That is handled by AP's and whatever happens to an AP cannot impact anything else. So my systems are close to 100% stable, it is extremely rare for me to see a reboot. I have one remote site powered by UPS that had been up for almost two years until the UPS battery failed recently.

    By reading up in the forums, you may find "sweet" combinations of settings that give best performance on a particular router. But there's no holy grail, everyone has his own particular favourite settings that work for him, but not necessarily for others.

    Dent - no idea where Teddy took it from, you may find that information in the archives.

    Noxolos - Broadcom has been repeatedly asked for many years, yes. They don't release their code. Period. (The was some hype about a released wireless driver a year or so ago but it turned out on inspection to be an unfinished example of a driver that hasn't ever been used in any router, as I recall).

    Have fun!
  17. CardinS2U

    CardinS2U Network Guru Member

    RT-N16 is very stable! Though the wireless performance is terrible when 10 devices connects. I fixed this by using RT-N16 wireless private (turning it off/hiding it). I connected Linksys e4200 running it as AP running very fast even with 19 devices connected. I left it running for a day open no secuirty what so ever and had close to 30 people maxing out my line speed.

    thanks for that AP idea toastman
  18. Dent

    Dent Network Guru Member

    I have an E4200 v1 running Victek's latest beta Tomato firmware designed for this router (v1.28.9011). I have also tried Toastman's RT-N firmware for this router. Now as I understand it, Victek and Toastman's firmware both use the same RT-N wireless drivers. Now has anyone noticed that the secondary wireless radio (the radio that is capable of 5Ghz but also 2.4Ghz if chosen) is so much weaker than the primary 2.4Ghz only radio. At first I thought it was because the 5Ghz signal was by nature always going to be weaker than the 2.4Ghz and I always had the secondary radio set for 5Ghz. But now I noticed that if I set the secondary radio to 2.4Ghz instead of the 5Ghz and even if I put the same settings as what I had for the primary 2.4Ghz radio, that the signal strength as measured with Inssider for this secondary radio is always weaker. The signal strength for the secondary radio measures as the same strength regardless if the radio is set to 2.4Ghz or 5Ghz and is always much weaker than than the primary 2.4Ghz radio.

    Now for those running an E3000 (which I do not have though), I understand that it runs quite fine and also is capable of dual-band mode with the regular RT drivers. Do those people find that the signal strength of the secondary radio running in 2.4Ghz mode has the same signal strength as the primary 2.4Ghz only radio?

    I haven't tried the regular RT driver firmware with my E4200 but I have read people say that the 5Ghz radio is disabled. Do you mean the secondary radio altogether is disabled or is it just the 5Ghz portion of the secondary radio that is disabled but the secondary radio is able to use the 2.4Ghz band if chosen?
  19. Toastman

    Toastman Super Moderator Staff Member Member

    The 2nd radio, which is intended for 5GHz, does not have 2.4GHz antennas on it, so it wouldn't be likely to be as strong as the "real" 2.4GHz radio.

    It was never intended to be used at 2.4GHz.
  20. Dent

    Dent Network Guru Member

    Thanks Toastman. And for others information, I tried out the latest Linksys E4200 stock firmware and measured the signal strength of both radios in InSSider and the results are the same signal strengths as with the Tomato firmwares.
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