E4200 2.4 Ghz 40Mhz [ Edited ]

[smitty870]

How do I force the router into 40MHz channel width for the 2.4 GHz band?  I think it's staying in 20 Mhz even when set to auto as I am only detecting 1 channel when using inSSIDER.  Any other router I have had when forced into or set for auto displays two channels on the 2.4 GHz band.  Since the router seems to only be using 20 MHz band it seems to only want to operate at 144 Mbps instead of 300 Mbps.

[gv]

You can't force it to 40 Mhz. If the router finds too much interference to operate reliably with a 40 Mhz band it automatically switches back to 20 MHz. This is almost all cases of interference better than using a 40 MHz band.

[smitty870]

So basically what your saying is this router is more senstive to interferance than my prior routers?   I have not had this problem prior to upgrading to the cisco.

[gv]

Maybe. Maybe not. Depends on your previous 802.11n router model.

Remember, that a 40 MHz setting on the 2.4 GHz basically allocates 2/3 of the total available band! Now take a few other 802.11g access points which randomly send data. This severely increases interference and thus usually reduces throughput. Thus, maybe you get a 300 Mbit/s connection but only 30 Mbit/s of actual throughput while with 144 Mbit/s you may get 70 Mbit/s.

The offered transfer rate of 144 Mbit/s/300Mbit.s or the bandwidth of 20/40 Mhz is NOT the problem. The problem is how much you actually get through there.

And even if you get a quite good result your neighbors won't be too happy about it...

[paulwang2000]

the decision should make by me not the system right? At lease I can chooise what I need rather than it tell me what I got. It is a normal option for all other product, why not this?

[gv]

It's a consumer product targeted people which don't know much about networking.

Not allowing to force 40 MHz avoids complaints from all those people which think they use the fastest possible settings by forcing 40 MHz (and highest power settings etc.etc.etc.), to get 300 Mbit/s connection. Then they complain to get only extremely slow transfer rates...

You don't see how much interference there is and noone is helped if two people run 802.11n routers with 40 MHz on 2.4 GHz, fighting for the bandwidth basically bringing the whole 2.4 GHz to a standstill in the proximity...

I would say only allowing Auto or 20 MHz doesn't seem like a bad idea at all. If you think you absolutely need 40 MHz forced, well, then get a different band's router and see what you get.

However, for instance Intel has the same policy on their 802.11n cards: you can set them to 20 Mhz only or Auto. You have no way to force an Intel 802.11n wireless adapter to 40 MHz, on either band, with their standard Windows driver. Thus, it's not only Linksys/Cisco who think it's maybe a bad idea to force 40 MHz...

[JEROME44]

why not give the consumer the choice ,my old d link 615 run at 300 no problem this one wont just give us the firmware choice then it our problem if we get bad signal.have to wait till tomato does a firmware update that will alow 5ghz and guest .

mental that youu have to seek 3rd party firmware

[gv]

If the consumer has the choice, you have to support this choice. If the consumer choose 40 MHz and gets bad throughput and calls support, support must troubleshoot this. Or people complain about bad throughput because they force 40 MHz in an environment with a lot interference. Or they complain about their Intel cards not being able to connect in 40 MHz only because they don't get that the Intel driver forces 20 MHz unless you change the setting.

Thus, giving the choice is not simply your problem. It's also problem of Linksys/Cisco and the support.

A lot of people don't understand anything about this and would simply choose the "best" setting and then don't get that exactly that setting causes the problem.

The 2.4 GHz is overcrowded in many places. Not allowing the user to make bad choices is a design decision.

If you don't like it, don't buy Linksys.

Don't complain about how they have designed it. If you don't like it buy a different brand.

[MHolley]

I was curious about this as well. I have a Linksys 350N. The stock firmware was awful so I went with DD-WRT on that router. Speeds (and more importantly, reliability) improved greatly...and I did force that router to 40Hz.

So far, I'm pleased with the stock firmware on my new E4200 (v1.0.03) and have seen better speeds in my house, both from far away and from up close. My next-door neighbor has a Wireless-N network, so I wouldn't be surprised if there was some fight for bandwidth. I wanted to try and force 40Hz (300Mbps) just to see if I could get even better results on the 2.4GHz network. So far when I'm close to the router (10 ft. away, same floor, no walls) I get 10-12 MB/s (Windows 7 file transfer reported rates/ Realktek RTL8191SE Wireless PCI-E NIC) 40ft away, 2 floors up, I now get 8-10 MB/s. Before, I was getting 8-10 MB/s nearby and 4-6 MB/s at a "distance".

Short of buying a dual-band card (I'm planning to upgrade my laptop next year), I think that 80-96 mbits/sec are pretty good. I rarely see theoretical speeds being reached on networks, so I don't know how much higher I could expect. One thing I learned about working with DD-WRT is that TOO many options can be a bad thing. I can appreciate the need to balance the load of support-related calls for consumer products versus providing complex configuration options for higher-end devices. There are other options for the "NOS" on the router if you want more control over the hardware, but keeping it relatively simple for the average end-user makes sense. I can accept that answer.

The only thing that seems weird to me is that when set the router Channel Width to 20hz only, the speed reported on my Windows Network "Status" defaults to 72.0 Mbps. When I set the router to Auto (20Hz or 40Hz), the status bumps up to 150.0 Mbps. So it seems as if my connection is defaulting to the higher channel width, but not getting the full potential "connection speed". Its hard to ignore, despite the fact that the throughput is better.

Ultimately, I think it boils down to a poor choice of words (either Microsoft or the IEEE protocol standards) when describing connectivity. When you see the word "Speed:" in your network status window...you can't help but expect it to show up as advertised. It feels like you've bought a sports car and found out it only goes up to 80 MPH when you really expected it to go up to 160 MPH. The truth is, everyone knows that you will generally only go 80 MPH (speed limit laws, highway congestion, city driving, awful MPG when you lead foot) but one can't help feeling like you were lied to. We're not! Its simply the evil that is marketing confusing the situation and complicating the lives of engineers and support staff everywhere. Blame the pointy-haired boss.

• Anyone getting better than 12 MB/s in large video/data file transfers from an Ethernet source to wireless destination device (and vice versa) in the 2.4 GHz Band?
• Which client NIC pair best (i.e. Intel/Broadcom/Atheros and model#) with this router? (In general)
• Can anyone recommend a 5GHz desktop and laptop NIC which would give him better results? (Or even 2.4GHz)

Think of it as the difference between various benchmark tests (i.e. 3DMark, ATTO, etc..) and real-world usage and results. Sometimes the "max score" isn't an indicator of true performance, and you should ask yourself if what you are really doing with the router (or your wireless network to be more accurate) is living up to its potential in day-to-day usage. If the network is stable, and you get consistent performance from various locations in your home/office (file transfers from server to client, downloads from the internet, streaming video(buffering/timeouts)) that are on par with the max practical speeds as seen by others...then just ignore those "red-line" Turbo bars in your network tuning tool and enjoy.

If they don't meet your expectations then I'd suggest:

1) Trying a new firmware...

2) Trying a new NOS ('cause its free)

3) Testing a new client NIC ('cause they're cheaper than a new router AND sometimes chipsets don't play well with one another)

4) Playing around with placement of devices relative to walls, other electrical devices, etc..etc..)

5) Wiring your house/office with Ethernet. (Because wireless speeds just suck compared to beautiful twines o' Copper)

6) If there are no reported specific problems (i.e. This Model Router doesn't work well with That Model PCI NIC) work with the retailer or Cisco to swap out the unit.

I can tell you that unless you are a business who depends on wireless (for revenue or for supporting customers) and can invest serious money in a wireless infrastructure, it is sometimes going to simply be hit and miss. Your neighbors cordless phone, your house's electrical wiring, your Zodiac sign....so many things can interact with consumer grade wireless routers. A different make and model might work simply because it has a different chipset...nothing to do with the vendor or their QC and programming skills. Your neighbor might have a broken router that spewing interference for a block. He might also have DD-WRT on it and he set everything to MAX and TURBO and completely washed out the local airwaves. He might also be a she from another planet whose pheromones are emitted as EMF pulses and the router that works today will be completely useless when she goes in heat. But I'm getting into rare cases which effect 1% or less of wireless users.

So, take a deep breath. Make some real world tests. (File transfers, internet downloads, media streaming, multiple devices) Come back, share the results, and lets go from there.....

Cheers.

[gv]

72 Mbps is a 20 MHz speed. 150 Mbps is a 40 MHz speed, i.e. the router is operating on 40 MHz.

The Realtek is a 1x2 MIMO card. It only supports 1 spatial stream for transmissions, i.e. the maximum speeds you see. In the opposite direction, you have two stream.

See here: http://www.realtek.com/products/productsView.aspx?Langid=1&PNid=21&PFid=48&Level=5&Conn=4&ProdID=226

I can't tell what Windows or the driver is showing exactly. It seems it only shows you the speed with which you can transmit but not the receiving speed. Of course, maybe the driver in the stock firmware of the E4200 doesn't support asymmetric setup of streams.

Generally, with wireless you won't see more than half the negotiated speed for transfer.