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balforth
Posts: 6
Registered: ‎07-01-2011

E4200 won't connect beyond 144mpbs

[ Edited ]

Just got the router and set it up...

 

On the 2.4ghz side, I'm set up on the cleanest channel (per inssider) which is 6, channel width is auto (although I've tried it fixed at 20 also), N-only, and security is WPA2 personal.  WMM support is enabled.  I'm running firmware 1.0.02

 

The laptops continually stay around 72mpbs, occasionally jumping to numbers in the 100 range... twice I saw it actually hit 144.  Inssider shows the max rate as 144, while other N networks in range are as high as 270.  I'm sitting right next to the router with 5 bars -- why is the max rate 144?  Why won't it run at 300?

Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: E4200 won't connect beyond 144mpbs

The router may detect too much interference and reverts back to 20 MHz bandwidth (72 and 144 are 20 MHz speeds). With a lot of interference, 40 MHz bandwidth won't really help you. 40 MHz bandwidth basically allocates 2/3 of the total available 2.4 GHz band for your router, thus dramatically increasing the throughput. As you can see other 802.11n routers with 40 MHz enabled even your throughput with 20 MHz may be impaired because of your neighbors which do their own little bandwidth "war".

In addition, please remember that many wireless adapters come with 20 MHz bandwidth by default on the 2.4 GHz band, e.g. the Intel drivers. These won't ever connect with 40 MHz band unless you change the driver setting.

Make measurements to see how much throughput you actually have transferring data from a wireless computer to a wired computer.

You may be able to get a 40 MHz bandwidth briefly after a reboot of the router. If that's the case, make another measurement in that situation and it may well be that your throughput is less then the measurement before...
balforth
Posts: 6
Registered: ‎07-01-2011

Re: E4200 won't connect beyond 144mpbs

[ Edited ]

Here are the available networks....

 

inssider.jpg

 

I guess I didn't realize that to achieve 300mbps you had to use 40mhz, which means you're using 2 channels simultaneously. 

 

The laptop I'm currently on does in fact have an intel wireless adapter...  I changed the settings for the adapter from 20mhz only to auto, but it's still the same... I'm assuming because the router is still only chosing to run at 20mhz...  Is there a way to force the router into 40mhz mode?  

Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: E4200 won't connect beyond 144mpbs

As you can see the 40 MHz network allocates channels 1-9 leaving little room for anything non-overlapping. In addition, you seem to operate another 11g access point. If in particular the 40 MHz generates a lot of traffic reverting back to 20 MHz seems a good idea. But as I wrote before, only actual measurements can give you a better answer.

All negotiated speeds have a specific set of parameters. 40 MHz is one of those parameters. You'll find a table listing all possible speeds here: http://en.wikipedia.org/wiki/IEEE_802.11n-2009#Data_rates

Please remember, that the connection speed is a theoretical boundary. It does not say how fast you can really transfer data. It only tells you which parameter where chose. They may change during a transfer. Thus make measurements. In general, you'll see only half of the connection rate or even less.

You cannot force the router to 40 MHz mode. Linksys seems to be very conservative with may configuration options which may cause complementary effects. I guess most users won't immediately understand why a connection on a higher rate (e.g. with 40 MHz) may have actual throughput then a lower rate (e.g. same parameters but 20 MHz). It doesn't help to force a router to 40 MHz to see a 300 Mbit/s connection but only 40 Mbit/s throughput while you might see 60 Mbit/s on a 144 Mbit/s connection with 20 MHz band.

Considering the amount of people which complain about the connections on the 2.4 GHz band and the observation that the E router often reverts to 20 MHz only may indicate though that they are too pessimistic with their choice to accept 40 Mhz or not.

As I wrote before, you may be able to see 40 MHz for a while directly after a reboot until the router receives too much interference and decides to go back to 20 Mhz.

Settings on the adapter are in the driver.
balforth
Posts: 6
Registered: ‎07-01-2011

Re: E4200 won't connect beyond 144mpbs

I found another one of your threads and found my answers:

 

http://homecommunity.cisco.com/t5/Wireless-Routers/E4200-2-4-Ghz-40Mhz/td-p/396433

 

I guess even with the other weak networks around me, it might be more detremental for me to run 40mhz...  I could live with 144, but it's still odd sitting directly next to the router and only seeing 72. 

 

I hope my 450mbps trendnet usb adapter sees better results when it comes in.  I will test everything with file transfers as well, as I realize the link rate doesn't necessarily have anything to do with actual throughput rates.

balforth
Posts: 6
Registered: ‎07-01-2011

Re: E4200 won't connect beyond 144mpbs

So with my old G only network, I was ftping files wirelessly from my laptop to my HTPC which is also connected wirelessly at an average rate of 1Mbps.

 

With the E4200, my test laptop connects to the 5ghz radio consistantly over a 200mbps link rate (currently at 270).  My HTPC is still connected via my old ASUS router/bridge running on the G network.  I was seeing an average of 2Mbps... when pulling from my HTPC back to this laptop, I was actually hitting 2.75mbps quite often.  **note -- this isn't the same laptop I was using in my above posts.  Anyway, there seems to be a big difference :smileyhappy:

 

The trendnet 450mbps usb adapter I mentioned earlier will replace the 802.11g bridge, so hopefully when that comes in, the next test will result in even better transfer rates.

Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: E4200 won't connect beyond 144mpbs

72 Mbps is with one spatial stream. 144 with two. Again, the exact reasons for this are difficult to find. You can only test various settings.

For measurements, only make tests from wireless to wired. Never wireless-wireless. All other measurements are not really interesting.
guimorato
Posts: 3
Registered: ‎11-09-2011

Re: E4200 won't connect beyond 144mpbs

Excuse-me

 

I read all the threads about the 144Mbps limitation on the E4200 and the explanations about interference and stability. I understand that there is a trade-off.

 

BUT why does CISCO advertise the E4200 model as "Transfer rates up to 300 + 450 Mbps speed for a premium home network experience" if it can NOT achieve a rate above 144Mbps?

 

I`m far from pleased and this can be called false advertising.

 

Where am I worong?

Expert
sabretooth
Posts: 5,329
Registered: ‎11-11-2008

Re: E4200 won't connect beyond 144mpbs

^^  Because under IDEAL conditions it is possible to connect at the rate.  However, you will be FAR from ideal and never achieve those rates.  Remember whatever you connect at the wireless speed, you will only transfer data at 50% of that rate (on a good day with a tail wind).

guimorato
Posts: 3
Registered: ‎11-09-2011

Re: E4200 won't connect beyond 144mpbs

Hi Sabertooth.
Thanks for your answer.
But if many other networks are appearing right now at 300Mbps HOW COME IT IS NOT POSSIBLE JUST FOR THIS MODEM?