Fast ethernet but slow wifi, might be a bad config?

Installing and Using OpenWrt Network and Wireless Configuration
#1

Dear all,

I am using a TP-Link CPE-210 V1 to connect to a public wifi on the street. Then I use the same CPE-210 to create another wifi so that my devices connect to it inside my house.

The problem is that when I connect to the CPE-210 with an ethernet cable I get decent speeds but when using the wifi for my devices it is sooo much slower, even at 1m from the CPE-210.

Please any ideas of what should I check? I can add any information / configuration that can help.

Result from speedtest.net:

  • Using computer connected with an ethernet cable to CPE-210: 3.3Mbps Download / 4.3Mbps Upload
  • Using computer connected with wifi to CPE-210: 0.8Mbps Download / 2.6Mbps Upload
  • Using computer wifi card from same position as CPE-210: 4Mbps Download / 4 Mbps Upload

These are the transmission rates of the different links:

  • Public Wifi - CPE-210: 11Mbits RX Rate / 11Mbits TX Rate
  • CPE-210 Wifi - Computer: 11Mbits RX Rate / 54Mbits TX Rate
  • Public Wifi directly to Computer: 11Mbits TX Rate

The speed tests indicate the problem is in the CPE-210 Wifi but it has the best transmission rates...

CPE-210 is using the latest available openwrt/lede firmware (17.01.4).

#2

your device only has one radio, so if you use it as wifi client and accesspoint, throughput will be reduced.

options:

  • move your wifi to the same channel as the public wifi and see if things improve
  • add a second radio to your router (usb wifi)
  • use a router with two radios
  • use two routers (with one radio) and split client and ap roles
1 Like
#3

Thanks fuller, I already tried what I could from your list:

  • My wifi and the public wifi are on the same channel (I cannot even change that, I guess because it is the same radio)
  • There is no way to add a second radio to a CPE-210
  • I do not have a router with 2 radios
  • I don't have another extra router

I know the throughtput will be reduced with 1 radio for 2 wifis but to the point of 0.8Mbps download next to the router? Plus, the upload is 2.6Mbps (it is a lot more). It seems like something else must be dragging the download speed right?

#4

Therethorically, it should be approximately half (~27Mbps); but there are many other factors (e.g. others on the channel, interference, noise between ISP, noise between router, etc.). The speed seems normal.

#5

The TP-Link CPE-210 has a max. transmission of 300Mbps. Half is 150Mbps. How does 150Mbps go to 0.8Mbps?

https://www.tp-link.com/us/products/details/cat-37_CPE210.html

#6

First off, your link rates are only 11 Mbps. This may be due to distance, antenna, any feed lines you have, or configuration that prevents higher rates that are provided by 802.11n and/or 802.11ac. For the latter, make sure your encryption is psk2+ccmp (or psk2+aes, which is equivalent) assuming the public wireless supports that. Also remove support for 802.11b/g and legacy rates, if your devices support 802.11n or later.

Now, working with 11 Mbps, half of that for throughput wouldn't be surprising, once you take into account transmission overhead, beacons, environmental noise, and everything else in the real world. Halve that again (at least, since you potentially can't send a received packet in the time slot immediately following, but "lose" a transmission slot) as you're receiving and sending the packets on the same radio. So getting "a few" Mbps out of that setup would be expected.

Agreed, 0.8 Mbps seems low, but getting 2-3 Mbps isn't surprising to me.

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#7

11 Mbps is the old b standard. Is that all the AP on the street supports? Generally it is not a good idea to put any g or n signals on the same channel that old b equipment is using. So you really should use the CPE only as link to the street and run an entirely different wifi system inside the house.

If you don't have another router you may be able to use Internet Connection Sharing to use the wifi card in the computer that is connected by wire as an AP for local distribution (on another channel of course) inside the house.

1 Like
#8

Good explanation, thank you.
The thing is that the public wifi has an old AP which has a max. rate of 11Mbps, so it must be 802.11b. I know that is slow, but, as I mentioned on the original question I am able to achieve real speeds of 4Mbps directly with my computer or with my Lede device (CPE-210). I would be happy with something around 2-4Mbps, which I understand is a realistic expectation.

The more I try I keep seeing a huge difference between download and upload speeds. Even if we take into account all the possible interferences (tx overhead, beacons, noise, etc) they would affect similarly upload and download right? Why am I getting 0.8Mbps of download and 2.6Mbps upload? Can't I improve that download to 2.6Mbps?

#9

I made some more tests. I measured the effective speed of the Lede device by ssh into it and downloading a file from it:

  • With ethernet cable: 17,5Mbps
  • With wifi: 9Mbps

The 9Mbps of the wifi seem reasonable since the link is 11Mbps. So why am I only getting 0.8Mbps when I go to the internet? Since I checked the link between the Lede device and the public wifi have demonstrated to achieve speeds of 4Mbps I believe some thing must be wrong with the internal routing in Lede.

Here is my setup:

  • Lede connects as "client" to public wifi with router at 192.168.1.1 and DHCP server
  • Lede acts as "Access Point" for my devices at 192.168.66.1 and has another DHCP server which assigns 192.168.66.X IPs to my devices

This way my devices are able to access internet as well as 192.168.1.X computers. I don't fully understand how... (firewall, vlans, interfaces)

Is there a better way I can dump my configuration?

#10

Wait...what do you mean "go to the Internet"??? You have default routes and no networking conflicts:

If you tested your speed between devices, you're OK. You're device is only responsible for the WiFi speed between the Public ISP and the devices directly connected to it.