Poor wired connection to wan speeds

[jhoyer02]

Hello,

I am stumped. I just got a new rt-n66u and I am having issues with the wan speed from wired connections. My connection is 50Mb/s - 25Mb/s. I setup up the router with quick internet setup. I then tested my speed at speedtest.net and got speeds of 50/22. I was happy with that. But after time (within hours to days) the speed has gone down, typically getting as low as 5mb speeds. Even after rebooting the router it doesn't clear up. If I bypass the router and plug my computer directly in the connection, it intermediately gets better and a slight bit faster 51/23. I've done this 4 different times and the speed has always gotten better.

Right now I only have one computer connected via a cat 6 cable. Tried plugging into different ports. I have tried multiple cat 6 cables from the router to the incoming inet connection. I have QOS turned off, no antivirus running. Another note, my old linksys wrt54g has gotten 25d/22u after weeks and weeks of running all my devices on it wireless and multiple wired connections. It never had a slow down issue.

Any ideas?

 

[jseven]

I'm experiencing much the same problem. I noticed this shortly after getting my RT-N66U (B1 version) in mid-July. I immediately installed Merlin's 3.0.0.4_372.30_2 firmware. For the first day, all of the speeds were great (wired, 2.4G and 5G), then everything slowed down significantly. My Time-Warner connection is only 15Mbps/1Mbps (so-called "Turbo"), but I was getting only 10-12Mbps with wired connections and 1-5Mbps on wireless connections. My upload speed dropped down to ~200kbps. I cleared NVRAM and setup the router again, which put me back to my nominal speeds, but only for a short time.

If I disconnected the WAN cable from the router and plugged the cable modem directly into my laptop, I got the correct speeds. When I then connected the cable modem back to the router WAN port, I'd often get good speeds (wired and wireless) again for a short time before things slowed down again. This was very repeatable.

I then upgraded to Merlin's 3.0.0.4_372.31 and had the same results. I found that if I stayed wireless only (no connections to the LAN ports), that I would maintain 15+Mbps/1Mbps speeds on both 2.4G and 5G, but once I plugged anything in to the LAN ports, it would be anywhere from a few minutes to a few hours before I'd get the slow speeds again.

Last week, I decided to see how long the fast speeds would be maintained over wireless connections only. I cleared NVRAM and changed no other settings (other than SSIDs and passwords). I found that I was able to achieve 15/1Mbps wireless speeds for about 5 days before the speeds fell back permanently to the slow speeds. For the past few days, I'm getting anywhere from 1-7Mbps on both 2.4 and 5G networks, with abysmal upload speeds (100-200kbps). I have yet to re-connect anything to the LAN ports.

One thing that I did notice (and may or may not be a useful symptom for diagnosing this problem) is that ping times to external IPs (such as www.google.com) would be 30-50ms when I was getting the fast speeds, and 400-900ms when I was getting the slow speeds.

I'm next going to fall back to Merlin's 3.0.0.4_270.26b firmware to see if that makes a difference.

Could this a N66U hardware problem? Problems between the router and the cable modem? Thanks in advance for any insight into this problem.

-Jim

 

[CaptainSTX]

Isolate Problem

You need to try and see where the problem is.

First test your LAN using something similar LAN Speed Test. Test both using an Ethernet cable connecting your PC to the router. Then test using both radios.

Then you test using another PC just to be sure that it isn't the problem.

If you can't duplicate the problem on your LAN then perhaps it is your modem or ISP.

 

[RMerlin]

Make sure it's not one specific device on your LAN slowing down everything else (for example, a computer running a forgotten P2P application, or online backup software). Try disconnecting everything but one computer.

Also, test without anything plugged to the USB ports of the router, as scanning/sharing from a USB disk can slow down performance.

 

[jim769]

I have a similar issue that is when I use a eithernet port on the router to pc the speed is only like 36 mbps download but wireless both 2.4 and 5 G my speeds are 58to60 down and 11+ up on all devices. If I hard wire right to the modem no router my speeds are as mentioned 60/11. Not a huge issue for me though all my devices use wireless unless I do a firmware upgrade. But never the less wired from the router has some kind of issue wireless is awesome.

 

[jseven]

Thanks for your responses. Regarding RMerlin's questions, I have been testing without a USB device connected to the router. I don't have any P2P software running, but I do have online backup software running on a Linux desktop which is connected via Ethernet. I guess I didn't figure that would affect the download speeds of the network too much (if at all) since that software just uploads at low data rates when files change (which hasn't been that often, lately). I'll disable that for a while and see how it affects performance.

CaptainSTX makes a good suggestion to test LAN speeds between computers to see if I can duplicate the problem within my network. When I get the time, I'll run some LAN speed tests with various combinations of wired/wireless devices.

Thanks again for the suggestions. I'll update if I'm able to make some headway with the problem.