Doubts about Archer C7 v2

Hi everyone,

I've bought an Archer C7 v2 router and I'll try to install/configure LEDE firmware.
I've read a lot (more or less) on OpenWRT/LEDE forum/wiki, and I think I understand all the steps I have to do for having sucess on it.
But, I have one doubt, about the Wifi on that router.

Is the LEDE firmware working fine in that router with 5 Ghz. band?
I've read many people (using OpenWRT, not LEDE) talking about problems and speed lost on 5 Ghz. band.
I have read something about a bug on the driver (ath10k). It's solved in LEDE firmware?

Which version on LEDE version do you recommend me, EU, Standard?
My router is from EU.

Thanks a lot for help,

I have two Archer C7 v2 units, one as my main router, another as an access point. I'm not aware of any known bug with ath10k...can you perhaps expand on that?

There's no real difference between the US & EU LEDE firmware versions, they're just to get past a check on stock firmware which requires firmware from the correct region, once you're on LEDE it doesn't matter.

Hi KevinDB,

Take a look here: https://forum.openwrt.org/viewtopic.php?id=53703

Thanks a lot,

I skimmed that thread and the reality is that my use case doesn't have a need for screaming edge/theoretical bandwidth chasing so I don't feel able to advise.

How the wireless driver backports to LEDE's linux 4.4 kernel is a mystery to me also.

Personally, if I were purely interested in headline bandwidth then I'd steer clear of any 3rd party firmware.

Speeds have been pretty good with OpenWRT trunk snapshots, i don't think you will miss original TP-Link firmware.

Ok!!!

Thanks a lot,

Hmm, thats a quick test with an early archer c7 v2. One site is comuter connected with a cable and the other (target) is a laptop on wifew. 5 and 2.4Ghz capale

    root@Archer-Lede:~# iwinfo
wlan0     ESSID: "just2confuse5"
          Access Point: E8:DE:27:*******
          Mode: Master  Channel: 40 (5.200 GHz)
          Tx-Power: 23 dBm  Link Quality: 62/70
          Signal: -48 dBm  Noise: -105 dBm
          Bit Rate: 6.0 MBit/s
          Encryption: WPA2 PSK (CCMP)
          Type: nl80211  HW Mode(s): 802.11nac
          Hardware: 168C:003C 0000:0000 [Qualcomm Atheros QCA9880]
          TX power offset: none
          Frequency offset: none
          Supports VAPs: yes  PHY name: phy0

wlan1     ESSID: "just2confuse5"
          Access Point: E8:DE:27*********
          Mode: Master  Channel: 1 (2.412 GHz)
          Tx-Power: 23 dBm  Link Quality: unknown/70
          Signal: unknown  Noise: -89 dBm
          Bit Rate: unknown
          Encryption: WPA2 PSK (CCMP)
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: unknown [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes  PHY name: phy1

root@Archer-Lede:~#



root@Archer-Lede:~# uname -a
Linux Archer-Lede 4.4.30 #0 Wed Nov 9 11:17:52 2016 mips GNU/Linux
root@Archer-Lede:~#


C:\Users\mee\Desktop\iperf-3.1.3-win64>iperf3.exe -c 192.168.1.104 -i 1 -w 1M -l 4K -b 850M
Connecting to host 192.168.1.104, port 5201
[  4] local 192.168.1.106 port 50771 connected to 192.168.1.104 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.01   sec  8.50 MBytes  70.5 Mbits/sec
[  4]   1.01-2.00   sec  8.70 MBytes  73.8 Mbits/sec
[  4]   2.00-3.00   sec  9.16 MBytes  76.9 Mbits/sec
[  4]   3.00-4.00   sec  8.77 MBytes  73.5 Mbits/sec
[  4]   4.00-5.00   sec  9.20 MBytes  76.9 Mbits/sec
[  4]   5.00-6.00   sec  9.15 MBytes  77.1 Mbits/sec
[  4]   6.00-7.00   sec  8.93 MBytes  74.9 Mbits/sec
[  4]   7.00-8.00   sec  8.92 MBytes  74.8 Mbits/sec
[  4]   8.00-9.00   sec  8.85 MBytes  74.2 Mbits/sec
[  4]   9.00-10.00  sec  8.55 MBytes  71.6 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  88.7 MBytes  74.4 Mbits/sec                  sender
[  4]   0.00-10.00  sec  87.9 MBytes  73.8 Mbits/sec                  receiver

iperf Done.

------------------------------------------------------------
5Ghz Network

C:\Users\mee\Desktop\iperf-3.1.3-win64>iperf3.exe -c 192.168.1.104 -i 1 -w 1M -l 4K -b 850M
Connecting to host 192.168.1.104, port 5201
[  4] local 192.168.1.106 port 50780 connected to 192.168.1.104 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  19.2 MBytes   161 Mbits/sec
[  4]   1.00-2.00   sec  19.5 MBytes   164 Mbits/sec
[  4]   2.00-3.00   sec  19.9 MBytes   166 Mbits/sec
[  4]   3.00-4.00   sec  19.1 MBytes   160 Mbits/sec
[  4]   4.00-5.00   sec  19.1 MBytes   161 Mbits/sec
[  4]   5.00-6.00   sec  19.0 MBytes   159 Mbits/sec
[  4]   6.00-7.00   sec  17.7 MBytes   149 Mbits/sec
[  4]   7.00-8.00   sec  17.9 MBytes   150 Mbits/sec
[  4]   8.00-9.00   sec  17.7 MBytes   149 Mbits/sec
[  4]   9.00-10.00  sec  17.7 MBytes   149 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec   187 MBytes   157 Mbits/sec                  sender
[  4]   0.00-10.00  sec   187 MBytes   157 Mbits/sec                  receiver

iperf Done.

C:\Users\mee\Desktop\iperf-3.1.3-win64>

Same test without any option

5Ghz Net

 C:\Users\meee\Desktop\iperf-3.1.3-win64>iperf3.exe -c 192.168.1.104
Connecting to host 192.168.1.104, port 5201
[  4] local 192.168.1.106 port 50814 connected to 192.168.1.104 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  13.1 MBytes   110 Mbits/sec
[  4]   1.00-2.00   sec  13.2 MBytes   111 Mbits/sec
[  4]   2.00-3.01   sec  13.0 MBytes   108 Mbits/sec
[  4]   3.01-4.00   sec  13.2 MBytes   112 Mbits/sec
[  4]   4.00-5.00   sec  13.2 MBytes   111 Mbits/sec
[  4]   5.00-6.00   sec  13.0 MBytes   109 Mbits/sec
[  4]   6.00-7.00   sec  13.2 MBytes   112 Mbits/sec
[  4]   7.00-8.00   sec  13.4 MBytes   112 Mbits/sec
[  4]   8.00-9.00   sec  13.4 MBytes   112 Mbits/sec
[  4]   9.00-10.00  sec  13.6 MBytes   114 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec   132 MBytes   111 Mbits/sec                  sender
[  4]   0.00-10.00  sec   132 MBytes   111 Mbits/sec                  receiver

iperf Done.

C:\Users\mee\Desktop\iperf-3.1.3-win64>iperf3.exe -c 192.168.1.104
Connecting to host 192.168.1.104, port 5201
[  4] local 192.168.1.106 port 50821 connected to 192.168.1.104 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.01   sec  8.12 MBytes  67.6 Mbits/sec
[  4]   1.01-2.00   sec  8.50 MBytes  71.8 Mbits/sec
[  4]   2.00-3.01   sec  8.62 MBytes  71.5 Mbits/sec
[  4]   3.01-4.02   sec  8.62 MBytes  72.2 Mbits/sec
[  4]   4.02-5.00   sec  8.50 MBytes  72.4 Mbits/sec
[  4]   5.00-6.00   sec  8.25 MBytes  69.1 Mbits/sec
[  4]   6.00-7.00   sec  8.25 MBytes  69.2 Mbits/sec
[  4]   7.00-8.00   sec  8.88 MBytes  74.3 Mbits/sec
[  4]   8.00-9.01   sec  8.25 MBytes  69.1 Mbits/sec
[  4]   9.01-10.01  sec  7.62 MBytes  64.0 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.01  sec  83.6 MBytes  70.1 Mbits/sec                  sender
[  4]   0.00-10.01  sec  83.6 MBytes  70.1 Mbits/sec                  receiver

iperf Done.

C:\Users\Jens\Desktop\iperf-3.1.3-win64>

I'm not an expert, but it looks great.
It's supposed the max speed for Archer C7 on AC+N (5 Ghz.+2,4 Ghz) is 218 MBytes, and your tests are about 187 MBytes.

It's not the top, but almost the top of wifi's router.

Im not sure. On 2.4Ghz it is, in iperf, half of 5ghz net. But if i try do download from a fast FTP i get 200Mbit down, dosent matter 5 or 2.4Ghz.

Hi,

Finally saturday I installed LEDE firmware in my Archer C7 v2.
Rigth now everything seems to work fine, but the wifi gave me more speed in the official TP-Link firm that in the LEDE firmware.

I tested the wifi speed before changing to LEDE, and now it's just a little slower than before.
I'll continue testing my wifi over the week to be sure of that "lost" of speed.

For me it's not a problem, but I think is good no know it.

Thanks a lot,

The "lost" of speed it was about a bad configuration on my router (my mistake).
Now AC Wifi is on 80 Mhz. and working like a charm!!!

Thank,s

On the 2.4 Ghz. wifi interface I had to add the option noscan '1' to make it work at 40 Mhz.
By default was working at 20 Mhz. instead of 40 Mhz. I had configured on the interface.

I think that's and old bug reported.

Thanks,

Hmmm, we have to set this noscan option? Anything else?

Thats what i see with noscan 1. Without there are no changes??

root@Archer-Lede:/etc/config# iwinfo wlan1 info
wlan1     ESSID: "just2confuse"
          Access Point: E8:DE:**********
          Mode: Master  Channel: 6 (2.437 GHz)
          Tx-Power: 23 dBm  Link Quality: 70/70
          Signal: -38 dBm  Noise: -92 dBm
          Bit Rate: 41.1 MBit/s
          Encryption: WPA2 PSK (CCMP)
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: unknown [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes  PHY name: phy1
root@Archer-Lede:/etc/config#

On the 2.4 Ghz. wifi interface I had to add the option noscan '1' to make it work at 40 Mhz.
By default was working at 20 Mhz. instead of 40 Mhz. I had configured on the interface.

I think that's and old bug reported.

It's not a bug.

According to the IEEE 802.11 specification, one has to scan for neighbouring Access Points prior to enabling 40 MHz channel width. If a neighbouring Access Point is found which might be negative affected by using 40 MHz width channels, it will not be enabled.

With noscan you are disable this check. Might give you more speed but most likely cause issues for surrounding wireless networks. Long story short: Don't do this, don't be a d***head!

Already with HT20 only four 2.4GHz channels can be used without having overlapping issues. With HT40 only two channels are left. Head to https://en.wikipedia.org/wiki/List_of_WLAN_channels for a more detailed explanation.

What i do not understand atm. 70Mbit on 2.4Ghz are ???good??? I did not get more - tested with iperf3 and 2 Wlan clients. If start 2 oder Option "P" i stand at 70Mbit as max.

My computers on the 20 Mhz. were connected to 65 Mb., and changing to 40 Mhz. now are connecting to 150 Mb.
Tecnhically maybe is better to be on the 20 Mhz., I can't discuss that (I'm not an expert), but, if have a computer/mobile... capable to be working at 150 Mb. by wifi, is "stupid" going at 65 Mb.

That's my opinion, of course.

I get the info from here:
https://forum.openwrt.org/viewtopic.php?id=68326

Forcing HT40 in the presence of other overlapping networks is not only creating problems for those networks, but also for yourself. HT40 is more fragile than normal 20 MHz wide channels, so the interference you inevitably receive from your environment has a much higher chance to introduce link disruptions than without it.

Every device working at 150 Mb. seems to be working fine right now (48 hours later).

If I detect some problems I'll post it here.