RT-N66U latency issue on 2.4GHz

[mikesas]

I am having significant latency problems on 2.4GHz connections (very high jitter and some packet loss). My son can't stay connected to any of the games on the Xbox Live, VoIP applications are poor and even just browsing the web lags some. I have tested 3 units now so I am thinking that I must be doing something wrong because surely I did not get 3 lemons nor have I seen anyone else commenting on a similar problem with this router.

Anyone having similar problems or have some suggestions that I should try?


More Background on what I have tried so far (on all 3 units):

1) I have tested with the shipping firmware .112, latest ASUS stock .162 & .178, and I have tried Merlins builds all with the similar results (newer builds are slightly better than .112)

2) I cleared the NVRAM after changing the firmware.

3) I have tested with all the other settings at factory defaults. I manually set the 2.4GHz channel to 1,6, & 11 with no improvement. I have set the bandwidth at both 20MHz & 40MHz with no difference.

4) I have tested it with the 5GHz radio turned off with similar results

5) Wired through the router is a very clean connection (very low jitter and no packet loss).

6) 5GHz connection is pretty good (some jitter and no packet loss), but I only have a couple of devices that support 5GHz and of course the range is not as good.

7) Crowding in the 2.4GHz signal does not appear to be a problem. It never was with my old WNDR3700v1 (that was taken out by lightning) and looking at inSSIDer, my neighbors WiFi signals are very weak (less than -80dB).

 

[SoCalReviews]

I am having significant latency problems on 2.4GHz connections (very high jitter and some packet loss)... Anyone having similar problems or have some suggestions that I should try?

Mikesas, 2.4Ghz is crowded frequency range not just from 802.11n routers but from many types of wireless devices... Bluetooth, headsets, older cordless phones, microwave oven leakage, etc..

-My suggestion for the wireless settings would be to try using the fixed channel setting for channel 1, 6 and 11 (and 14 if permitted in your country or region). Set your bandwidth to 20Mhz and thoroughly test each one of those channels at a time with all the wireless devices you are using. You likely will find that one of those three channels works better than the others. If you are still having problems test each one of those channels at the 40Mhz bandwidth only setting. If you still have problems after that try channels 3 and 9 in 20Mhz bandwidth mode.

-Not all lag problems are because of wireless. Do you have lag problems with a direct wired Ethernet connection to the router also? There could be other problems associated with the router and its other settings or your modem. I Make sure your antennae are firmly tightened down on the router. Check to see if your router is getting good ventilation...using the provided stand or wall mounting is preferred for heat dissipation. Placing the router in a ventilation restricted area such as an enclosed cabinet can cause the router to overheat and cause lag, slowdown or a malfunction. Try turning QoS "off" if it is on (or on if it is off with appropriate settings for your VoIP or other devices) to see if that feature is causing issues for your devices.

-Make sure your router is using the proper DNS ...either supplied and applied in the router settings automatically from your modem or if you manually entered a DNS in the router settings...This can be a major issue of internet lag...pages coming up slowly, video lagging and stuttering, etc.. If you suspect your lag problem is related to your ISP's DNS server you can manually change it in the router... https://developers.google.com/speed/public-dns/ . Users report different results using public DNS servers. Sometimes using your ISP's provided DNS server is best because of its proximity to your location and for some internet users using a DNS server like Google's public DNS server works better because there may be latency problems with their ISP's DNS server.

-It may not have been a problem with your previous router but if your cable or DSL modem is running NAT (which results in double NAT if the router also has NAT enabled) then you could try changing your cable or DSL modem to bridge mode. I did this with my DSL modem and the responsiveness with my internet connection improved noticeably...especially for PS3 internet gaming.

-The first week I used my Asus RT-N66U there was a very strange problem I was having with my Ethernet connected desktop computer relating to certain applications lagging, not running properly or just not working when they needed to access the internet...and I sort of stumbled on the source of the problem and a solution...

My RT-N66U router came shipped with the time and date region zone set to a city in China. When I changed the router settings for my region the problems I was having with the applications on my computer disappeared. For security and licensing many of today's applications and some devices rely on specific accurate regions or time zones to work properly. Not having the time zone and DST set properly to your specific region can cause issues of lag or applications not working at all. Go into the router's settings under Administration > System > Time Zone and make sure all your time and DST settings for DST start and end are correct for your location. You can also customize a specific NTP server for your region...see http://support.ntp.org/bin/view/Servers/WebHome for more information.

 

[mikesas]

Mikesas, 2.4Ghz is crowded frequency range not just from 802.11n routers but from many types of wireless devices... Bluetooth, headsets, older cordless phones, microwave oven leakage, etc..

Thanks for taking the time to respond and provide some suggestions. I have been concerned that it is some other factor in my house since I have had the same problem three different N66U's, but the strange thing is that it has never affected any of my previous wifi routers.

-My suggestion for the wireless settings would be to try using the fixed channel setting for channel 1, 6 and 11 (and 14 if permitted in your country or region). Set your bandwidth to 20Mhz and thoroughly test each one of those channels at a time with all the wireless devices you are using. You likely will find that one of those three channels works better than the others. If you are still having problems test each one of those channels at the 40Mhz bandwidth only setting. If you still have problems after that try channels 3 and 9 in 20Mhz bandwidth mode.

Tried all that (see #3 in my original post), but I will give channels 3 & 9 a good test

-Not all lag problems are because of wireless. Do you have lag problems with a direct wired Ethernet connection to the router also?

Direct Ethernet is good (see #5 in my original post)

There could be other problems associated with the router and its other settings or your modem. I Make sure your antennae are firmly tightened down on the router. Check to see if your router is getting good ventilation...using the provided stand or wall mounting is preferred for heat dissipation. Placing the router in a ventilation restricted area such as an enclosed cabinet can cause the router to overheat and cause lag, slowdown or a malfunction.

It is on it's stand and out in the open well ventilated

Try turning QoS "off" if it is on (or on if it is off with appropriate settings for your VoIP or other devices) to see if that feature is causing issues for your devices.

I have not turned QOS on yet, but I can try that. The lag is so bad at times that you can tell when browsing. I have been using pingtest.net and a ping analyzer app. I get jitter in the 100's of ms and lost packets just pinging the router itself from a wireless client on the LAN side! Pinging something on the internet is worse.

-Make sure your router is using the proper DNS ...either supplied and applied in the router settings automatically from your modem or if you manually entered a DNS in the router settings...This can be a major issue of internet lag...pages coming up slowly, video lagging and stuttering, etc..

I use open dns and don't think that is the problem as I have no lag on the direct Ethernet and 5GHz wireless connections plus note my answer above using pingtest.net. No dns used when running a ping analysis.

-It may not have been a problem with your previous router but if your cable or DSL modem is running NAT (which results in double NAT if the router also has NAT enabled) then you could try changing your cable or DSL modem to bridge mode. I did this with my DSL modem and the responsiveness with my internet connection improved noticeably...especially for PS3 internet gaming.

The Wan address on the router is my outside ip address so I don't believe there is any other NAT from my cable modem.

-My RT-N66U router came shipped with the time and date region zone set to a city in China. When I changed the router settings for my region the problems I was having with the applications on my computer disappeared. information.

Time zone is set correctly on mine.

 

[SoCalReviews]

It sounds like more diagnostics required to solve your wireless signal problems

Mikesas, I like reading about your diagnostic process of trying to narrow down the source of your problems. As you know this is an extremely popular router so there is a large user base that has had a positive experience using it. That makes me even more curious as to exactly what is causing the problems you are experiencing.

I do know that changing the settings such as changing from auto channel to fixed channel and choosing the right channel has made a big difference in wireless reliability not just for my RT-N66U but for my Netgear WNDR3700v2 and the Linksys E4200v1 (when I had the 2.4Ghz wireless turned on) that I own. I am running the Netgear 3700 and the Asus RT-N66U right now with no problems despite living in an area with a fairly crowded 2.4Ghz spectrum. While I am broadcasting with two routers I have six to ten other networks being broadcast in my local area that I can detect but most of their signals are relatively weak inside my residence.

What I would focus on is what other possible interference or factors are effecting your wireless signal on the 2.4Ghz band. You say that you didn't have these problems with other routers but logically there must be something different about your residence and area that is effecting your RT-N66U differently than other users who have it in their residence. I would recommend starting out with the latest official firmware from Asus when you are trying to diagnose the source of your wireless latency problems. Also, besides differences in firmware...there are also variables and potential conflicts between different wireless radio hardware and the hardware and/or firmware (or software) that different wireless devices use.

Compared to my other wireless routers the Asus router with the external antennae seems to provide a much stronger signal to the devices I use. It does seem to have a higher sensitivity and to get maximum performance from it I have had to tweak the settings as I explained above by setting it to fixed channels that worked the best. Before making those changes that I noticed less reliable and erratic wireless performance and I was also having problems with some of my wireless Bluetooth devices like my wireless Mac keyboard and track pad as my Asus router auto changed to difference channels by itself at various times. Fixing the channels solved those problems. I don't believe that this problem was specific only to the Asus router but I believe the Asus router may have made the problem more apparent because it broadcasts with a stronger signal and possibly has a higher sensitivity than the other wireless routers.

I believe the only thing left for you to do is try a few other things to see if your Asus is picking up interference on the 2.4Ghz band from another device in your house...such as a 2.4Ghz telephone, Bluetooth devices, etc.. Try changing the router's Tx power setting from the default of 80mw to a lower setting such as 40mw or to a bit higher setting such as 100mw and see if the signal problems get better or worse. Turning down the Tx power setting can sometimes help improve signal quality. Make sure your Asus isn't too close to any other 2.4Ghz devices in the same room. If possible move those devices away from it or into another room. Try changing the location of the Asus router to another location in the room or try mounting it on the wall at height above desk level or several feet above desk level if you can. Mounting it as high as possible above desk level and above other objects in the room should improve its signal to the rest of the house. I have mine wall mounted about two feet above desk level in a corner of the room with the antennae pointing side ways...all three vertically straight... to the right and pointing to the corner.

Even though most people wall mount it with antennae at the top I like the aesthetics of the sideways mounted look and it seems to ventilate well mounted side ways against the wall since there are openings in the case on both sides which means the heat ventilates from the bottom of the router and out to the top. The reason I brought up the heat issue is that excess heating can make the router's wireless radio malfunction even though the Ethernet connection may still be stable and these newer routers do seem to get much hotter than the older ones.

I don't know if you have tried using any application software to detect wireless frequencies being broadcast in your area but that would be the next step I would take. There are a number of free apps for smart phones such as Wifi Analyzer for Android and some PC applications for your desktop or lap tops computers that help analyze broadcast network signals in your area. I hope you are able to resolve the wireless issues you are having and when you can... keep us informed here of your progress so that we can also learn from your experience.

 

[mikesas]

I agree. I am quite puzzled by what is causing my problems so consistently across three different units when so many other people are having such great luck with this router. You could say I have gotten a bit stubborn about wanting to solve this.

I actually run two wifi routers in the house although one is just configured as a wireless access point hard wired to the other. To eliminate the extra variables, I have been doing my testing with the radios turned off on the other router which is another WNDR3700v1 (it was plugged in to a UPS during the storm). If I can get the RT-N66U working correctly, I think I will be able to cover the whole house with just the one.

For now I am using the RT-N66U as just a router and wired the WNDR3700 as an access point which works well minus the slight lack of coverage. I have swapped the config and tried using the RT-N66U as the WAP and moved it to a couple of different locations where I could still connect it with no significant change in results. If it is an external factor in my house impacting it which I agree seems most likely, it is somewhat pervasive across multiple locations in the house. It is odd how the netgear does well in either location in the house, but the RT-N66U is consistently no doing well in either location.

I have scanned the signals using inSSIDer on my laptop and the my neighbors signals are all very weak. They show up as less than -80dB and tend to fade in an out.

I had previously tried setting the Tx power and 100mw and 60mw with no change either. I can try 40 also and see if it helps. All my cordless phones in the house are the 5GHz variety. I had gotten rid of the 2.4GHz phones a while ago to avoid the conflicts with the WiFi. I have a few wireless mice that probably run over 2.4GHz, but they are such short range that I'd be surprised if they are a factor here, but certainly easy enough to test.

Please do keep the suggestions coming, I will let you know if I find a solution.

 

[SoCalReviews]

Mikesas, My Netgear WNDR3700v2 and my Asus RT-N66U are wall mounted next to each other with one above the other. They are broacasting on two different channels...The Asus on 2.4Ghz fixed channel 1 and the Netgear on fixed channel 9 with both set at 20Mhz bandwidth (40Mhz only or 20/40Mhz also works very well for me). The radio power is default setting on both. I mainly use the 2.4Ghz wireless for my PS3 machine for online gaming two rooms away from where the routers are located. I can easily switch my PS3 settings to connect to either one. I have tried swapping the cable and dsl modem cables for the routers and the result is the same. The Asus wireless router seems to be better.

The signal strength for the Asus and internet responsiveness with the absence of lag is unquestionably improved and seems to be much more stable than the Netgear 3700 or any of the other routers I own... the Linksys E4200 or the older Linksys WRT54G with high gain external antennae. It doesn't matter if I swap the channel settings. The Asus wireless signal strength is up to 20% stronger according to Wifi Analyzer for Android. The PS3 signal quality for the Asus always shows 100% signal quality compared to 75-87% with the Netgear 3700.

I noticed the improvement in my internet gaming (Call of Duty MW3) right away with the RT-N66U. It's by far the best signal and most lag free wireless signal I have ever used with the PS3 for internet gaming which is one of the most latency sensitive active applications you use to test real applications with these wireless routers. I have to believe there is something you are overlooking that I mentioned. Unless you received several defective routers from Asus I really suspect something is different with your router settings or your environment.

Are you sure you didn't enable other settings different from default?...such as enabling DoS attack protection instead of keeping the default setting of disabled. Do you have multiple guest networks enabled? Are you using WPA2 Personal with AES?...Any other setting such as WPA or WEP will not enable the full potential of a wireless N specification signal. Try changing your router settings to default with the Asus firmware and make sure you have set to a fixed channel.

Maybe there is some strange incompatibility between the Asus and your internet modem but that wouldn't account for the wired Ethernet working ok. Have you tried changing your Ethernet cable connecting your router to your modem? I use all Cat7 shielded Ethernet interconnect cable between my routers and modems. When I debug a problem I usually go through all the possibilities. Hopefully one of the wireless solutions discussed here hasn't been overlooked. If I come up with another idea to look at I will let you know. In the meantime I hope you stumble upon a solution.

 

[mikesas]

Are you sure you didn't enable other settings different from default?...such as enabling DoS attack protection instead of keeping the default setting of disabled. Do you have multiple guest networks enabled? Are you using WPA2 Personal with AES?...Any other setting such as WPA or WEP will not enable the full potential of a wireless N specification signal. Try changing your router settings to default with the Asus firmware and make sure you have set to a fixed channel.

I always use WPA2/AES, but I even tried also setting it to be completely open and still had the same very high jitter and packet loss. I have not turned on the any of the guest networks and I have restored the factory defaults multiple times. No difference. In fact nothing I have tried (tweaked many settings) seems to make any difference. I always manually set the channel also, although I gave Auto a try with no difference.

Signal strength on the RT-N66U is definitely higher than the WNDR3700v1. Signal strength is not the problem. It is either external interference which I can't identify or something is bogging down the processing internally, but only through the 2.4GHz connection. Wired and 5GHz are great. You are asking the right questions.

It will be another 8 days before I am home again to do more testing, but keep the ideas coming.

 

[thiggins]

How are you testing for jitter and packet loss? To a wired client on the LAN or to an Internet source. If the latter, try testing from wireless to a wired LAN client. A long series of pings should do it.

What wireless clients are showing the problem (make, model)?

 

[mikesas]

Tim,

I only began testing after observing issues during typical every day usage with the most obvious problem being my son's inability to play games on an xbox360 to noticeable lag web browsing across multiple devices (laptops, a desktop w/ PCI wifi adapter, iPad, etc.) connected via wifi yet my wired desktop was working great.

I started by using pingtest.net but the results would fluctuate quite a bit on the wifi connected laptops & desktop, but never really good. And of course my wired desktop consistently scored well. I then moved to using a Ping Analyzer app on my iPad and tested pinging the router itself and my windows desktop and a linux server which are both wired to the router with similar, but slightly more consistent poor results. I then also ran similar tests using a Dell E4300 laptop (has a Broadcom wireless N chip) also with similar results.

Although I did not do as extensive testing with them, the desktop with the PCI adapter has Ralink RT2860 chip and another laptop which uses an Intel Centrino.

 

[thiggins]

You can only control latency on your LAN. Once packets hit the 'net, you have no control. So focus on data from pinging the router to debug your problem.

802.11n is not known for its throughput or latency consistency. A glance at the IxChariot plots in the reviews usually shows high throughput variation. Latency plots would pretty much track throughput.

Most consumer wireless manufacturers tune their products to maximize average throughput. Minimizing throughput variation usually doesn't come into consideration.

Some routers are better than others at minimizing throughput variation. The RT-N66U is Broadcom-based. Why not try a WNDR3800? It uses Atheros wireless. You can also use the Router Finder to find others.

 

[SoCalReviews]

If gaming is where the biggest problem is with the latency I wonder if using a different brand of separate wireless bridge, access point, etc. for the XBox 360 (connecting to the 360's Ethernet port) would work better instead of using it's built in wireless or supplied adapter. It is odd though because I have read many posts and reviews where people are using XBox 360 with the N66U with no problems. Maybe the latency issue is just a conflict with specific wireless N hardware in one of the models of the XBox 360. There might be more information about this on the MS XBox 360 support site. Update: I just noticed the other thread discussing this issue of XBox Slim model connectivity problems after I posted.

 

[thiggins]

You are not alone
http://forums.smallnetbuilder.com/showthread.php?t=7774

 

[mikesas]

Some routers are better than others at minimizing throughput variation. The RT-N66U is Broadcom-based. Why not try a WNDR3800? It uses Atheros wireless. You can also use the Router Finder to find others.

Thanks for the advice Tim. I went ahead and picked up a WNDR3800 and so far it is working great.

I am not sure why I spent so much time fussing with the RT-N66U. With all the praise it has been getting, I could not understand why I was having such a unique problem. I guess I just wanted to figure out the cause. Maybe something in my house is not agreeing with the Broadcom chip, but the Atheros based WNDR3800 is working great.

 

[thiggins]

Glad it worked out for you. This is a good example of why router selection is such a personal process.

 

[cybercp]

Hi mikesas

I've exactly the same problem, i have tried all channels with 20Mhz or 40Mhz and tried all types of encryption like wep, wpa/wpa2. also I have tried different kinds of firmware eg tomato Shibby ver 8x to 100 and original Asus firmware. but still have same problem. checked that the 2.4GHz signal only have 20% may be less even the wireless device and router put on the same desk (already asked Asus to replaced a new one), and changed router from n66u to Asus RT-N16, also have same problem.
Finally, changed router to TP-Link WR1043ND (Atheros Chipset) without any problem. seems related to Chipset itself. I can say the Asus Broadcom chipset not compatible with my HOME environment.
Now still trying to find a solution. will let you know once i find a solution

 

[darknight]

Add another one to the list. Once in a while this happens:

Pinging 192.168.1.1 with 32 bytes of data:
Reply from 192.168.1.1: bytes=32 time=267ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1247ms TTL=64
Reply from 192.168.1.1: bytes=32 time=7ms TTL=64
Reply from 192.168.1.1: bytes=32 time=50ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=2ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1352ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1913ms TTL=64
Reply from 192.168.1.1: bytes=32 time=21ms TTL=64
Reply from 192.168.1.1: bytes=32 time=982ms TTL=64
Reply from 192.168.1.1: bytes=32 time=2ms TTL=64
Reply from 192.168.1.1: bytes=32 time=942ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1926ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64​

I get a solid 25 Mbps by Ethernet and sometimes drops down to below 1 Mbps. Client is 10m away through a flimsy wall. Am I wrong to expect my full 25 Mbps at this distance?