OpenWrt very slow on raspberry Pi 2

Installing and Using OpenWrt
1

Running openWRT on an older RPi2 with 2 WiFi dongles as a travel router. However trougput speed is very slow (< 2mBit/s). I'm not expecting an RPi2 to be blazing fast, however <2 mBit/s seems too slow even for this Pi

1 dongle connects to (public) wifi.
1 dongle generated a new WiFi SSID to connect to

/etc/config/network

config interface 'loopback'
        option device 'lo'
        option proto 'static'
        option ipaddr '127.0.0.1'
        option netmask '255.0.0.0'

config globals 'globals'
        option ula_prefix 'fd36:7f65:eca9::/48'
        option packet_steering '1'

config device
        option name 'br-lan'
        option type 'bridge'
        list ports 'eth0'

config interface 'lan'
        option device 'br-lan'
        option proto 'static'
        option ipaddr '10.6.6.1'
        option netmask '255.255.255.0'
        option ip6assign '60'

config interface 'wwan'
        option proto 'dhcp'
        option peerdns '0'
        option dns '1.1.1.1 8.8.8.8'

/etc/config/wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'platform/soc/3f980000.usb/usb1/1-1/1-1.4/1-1.4:1.0'
        option channel '1'
        option band '2g'
        option disabled '0'
        option short_gi_40 '0'
        option cell_density '0'
        option htmode 'HT40'

config wifi-iface 'wifinet1'
        option device 'radio0'
        option mode 'sta'
        option network 'wwan'
        option ssid 'Pretty Fly For a WiFi'
        option encryption 'psk2'
        option key '111111'

config wifi-device 'radio1'
        option type 'mac80211'
        option path 'platform/soc/3f980000.usb/usb1/1-1/1-1.2/1-1.2:1.0'
        option band '2g'
        option disabled '0'
        option channel '1'
        option cell_density '0'
        option htmode 'HT40'

config wifi-iface 'default_radio1'
        option device 'radio1'
        option network 'lan'
        option mode 'ap'
        option ssid 'Topvorm.Net'
        option key 'Topvorm.net'
        option encryption 'sae-mixed'
        option wmm '0'
2

And you know the public wifi is faster than 2mbit?

3

'Public' wifi is currently my own Wifi. VDSL up to 100mbit/s

4

Then you probably need to post lsusb so we can see the radios used.

5

Bus 001 Device 004: ID 7392:7822 Realtek 802.11n WLAN Adapter
Bus 001 Device 005: ID 7392:7822 Realtek 802.11n WLAN Adapter
Bus 001 Device 003: ID 0424:ec00
Bus 001 Device 002: ID 0424:9514
Bus 001 Device 001: ID 1d6b:0002 Linux 5.10.161 dwc_otg_hcd DWC OTG Controller

6

If you use the cli wifi stick and wired lan, instead of wifi-rpi2-wifi, is the speed the same?

7

Wifi stick 1 connected to 'public' wifi and client PC hard wired to RPi ethernet gets me up to about 13mbit now. Still not trailblazing, but that might be the speed you could expect from an RPi 2

8

Or Realtek wifi, it's not great, esp in AP mode.

9

Any suggestions on 'good' dongles in AP mode?

10

Take the money you'd blow on yet another set of USB WLAN cards and spend it on a made for purpose (small) wireless router instead, which will give you better results for not much more money.

2 Likes
11

But will not give me the fun and learnings from doing it myself :wink:

12

In return of the satisfaction of stuff actually working with decent performance and reliability - and actually being rugged enough to survive more than one travel.

2 Likes
13

Per @slh's point, you can buy a purpose built travel router for relatively cheap. Many of them are supported by OpenWrt, so you can install the official OpenWrt and learn on that... including getting various USB wifi sticks up and running if you really want (although the built-in wifi will probably be better, but for the learning experience, go for it).

14

I know what my 'buy' options are. Yet i have an old RPi 2 lying around and have relatively easy access to different USB dongles. So i'll be more than happy to continue my quest by using a 'good AP' adapter.

15

I agree with the others, but if you really want to go down that rabbit hole, have a look at https://github.com/morrownr/USB-WiFi

The RPi2s USB ports might be under powered for some of those devices (usb3 ones for sure).
A powered USB hub might be required.

16

By all means. As long as there is benefit to you (in terms of learning, a project you're excited about, etc.), keep going. But know that with respect to "good AP" USB adapters, there really aren't many in this category. Almost all of them are designed with the primary intent as a STA mode device (some don't support AP mode at all), so they aren't optimized for this use. And the radio architecture (often 1x1) and antenna design (usually small PCB traces, sometimes external) is not going to yield great performance, especially with multiple STA mode devices connecting to it.

@frollic has proved a useful link, but if you find others that are interesting, please post here for the benefit of future readers. And, in that same vein, report back on your efforts -- both successes and failures, so that we can have more info on the forum.

1 Like
17

Two radios on the same band in close proximity will jam each other even if set to different channels (and here you have not even set them to different channels). It is likely to work better using one radio as AP and STA combined, if the driver supports that. With a single radio time synchronization is better.

Don't try to use HT40 on 2 GHz unless there are absolutely no neighbors. Your two radios count as neighbors.

Start with a speed test wireless-wired. About 30-40 Mb net throughput is the best that a 1x1 radio on 2 GHz can do. A repeater scenario will lead to half of that.

1 Like
18

Could you try to use different channels for the 2 wifis?

19

There is no fun in a Raspberry Pi pretending to be a wireless router. Trust me on that.

Just frustration, from what I've seen on these forums.

2 Likes
20

A worthwhile experiment would be to use a USB-ethernet adapter so you have 2 ethernet interfaces. Use one as a "lan" and the other as a "wan" (or second lan) and then run iPerf between them (using computers on either side). This will give you an idea of your maximum routing speed (remember, also limited by the 100Mbps ethernet and USB 2.0 speeds, but I don't even know if the CPU is powerful enough to saturate that in a routing context).

1 Like