AP causing huge download speed slowdown

[jappleton9]

Hello,

I'm having an issue strikingly similar to this thread:

http://www.tomshardware.com/answers/id-1693738/router-wireless-access-point-slow-download-speed.html

The solution to that one seemed to be a combination of luck and voodoo magic, which isn't working for me.

Some more details on my setup:

I have a netgear modem/router combo in the corner of the basement with built in wifi. The wifi only cover basically the basement and room right above it. I have two other computers in basically the furthest opposite corners of the house with ~100-150ft ethernet cables ran. There is a switch run right off the modem to these cables and a few others around the house. When the cables are hardwired directly from the switch, all the end points get speeds of around 100-125 mb/s download and around 10 upload. I am trying to add two n600 routers as access points to each of the computers on the ends to cover the wifi across the upstairs and outside area, and theoretically...they work. but speeds drop to 10-15 mb/s on the download side while upload stays roughly the same. I tried using the AP mode setting on the routers and manually configuring them as AP's, but nothing seems to increase the speed. If there is any other info I can provide that would help please let me know.

Thanks in advance for any help.

 

[bill001g]

As indicated in that thread when you run multiple radios you have to be sure the radios frequencies do not overlap. You also need to be sure you are testing on the proper AP. I would run different SSID to start so you are 100% sure you are connected to the device you think you are.

Next force the devices to use 20mhz only. If you set it to 40mhz you get instant overlap since there is only a total of 60mhz on the 2.4g band. You would then set the AP to channels 1,6,11. You also need to see what your neighbor is using to try to avoid it but that has become almost impossible.

You will never get 100m out of a 802.11n router. It depends on lots of things... like being able to run 40mhz bands and have 2 antenna on the end nic cards. If you were to run a single antenna on 20mhz the max you can get is 65m and you get nowhere near that. Your 10-15m is slow but I would not expect more than about 30-40m if you run 20mhz channels. Even if you run it at 40mhz with 2x2 mimo (which is what the 300m number represents) you might get 60-70m in real life tests. Even the top of the line routers that are claiming over a gig of speed using 4 antenna and stuff on 802.11ac actually do not get much more than 300m on testing sites.....and that assumes you have the non-existant nic cards that have 4 antenna.

 

[jappleton9]

As indicated in that thread when you run multiple radios you have to be sure the radios frequencies do not overlap. You also need to be sure you are testing on the proper AP. I would run different SSID to start so you are 100% sure you are connected to the device you think you are.

Next force the devices to use 20mhz only. If you set it to 40mhz you get instant overlap since there is only a total of 60mhz on the 2.4g band. You would then set the AP to channels 1,6,11. You also need to see what your neighbor is using to try to avoid it but that has become almost impossible.

You will never get 100m out of a 802.11n router. It depends on lots of things... like being able to run 40mhz bands and have 2 antenna on the end nic cards. If you were to run a single antenna on 20mhz the max you can get is 65m and you get nowhere near that. Your 10-15m is slow but I would not expect more than about 30-40m if you run 20mhz channels. Even if you run it at 40mhz with 2x2 mimo (which is what the 300m number represents) you might get 60-70m in real life tests. Even the top of the line routers that are claiming over a gig of speed using 4 antenna and stuff on 802.11ac actually do not get much more than 300m on testing sites.....and that assumes you have the non-existant nic cards that have 4 antenna.

I went ahead and set up the AP with different SSID names to be on the safe side. I don't think the problem is actually on the wifi side. I'm still getting a significant drop on the wired connection too. If i go Modem > switch > computer I get 125 mb. If i go modem > switch > router (AP) > computer I get 10-15 mb, even when wired all the way through.

 

[bill001g]

That would be very strange. A AP when you run it on wired ports is a switch so it should work the same as if you put in a cheap 4 port switch. I guess you could turn the radio off to make it a switch and eliminate the wireless as the source to the problem

Be very sure you do not conflict on the IP addresses assigned to the AP.

Not sure if the router will tell you but you want the port to be running at 1g or at least at 100 full duplex. It would be rare to get it into half duplex but that can causes massive slowdown problems.

 

[jappleton9]

That would be very strange. A AP when you run it on wired ports is a switch so it should work the same as if you put in a cheap 4 port switch. I guess you could turn the radio off to make it a switch and eliminate the wireless as the source to the problem

Be very sure you do not conflict on the IP addresses assigned to the AP.

Not sure if the router will tell you but you want the port to be running at 1g or at least at 100 full duplex. It would be rare to get it into half duplex but that can causes massive slowdown problems.

I actually had a cheap 4 port switch laying around and threw it in to see what would happen. Low and behold, it still stayed around 15 mb. I tested both cables to the computer directly and both cables seem fine as well. Is there some sort of setting on the c3700 modem maybe that limits the number of pass through devices? I'm totally at a loss on why a switch wouldn't work.

 

[bill001g]

Even if it had a limitation ability it is not something that is accidentally setup it is actually fairly hard to do on consumer grade equipment even when you want to limit.

It almost has to be something with the auto speed negotiation not working correctly. Try your switch on a short cable next to the router. Since it happens on multiple device I would suspect the cable is the issue. These types of things are when it would be nice if TDR meters didn't cost so much. Some devices are just more sensitive to a cable that is slightly below spec, generally it is a issue with the way the end is attached but lately there is more copper clad aluminum cable being sold and that does not meet the standards and has strange issues also.