Super slow download, fast upload - reason?

Installing and Using OpenWrt
1

Hi, so I am struggling with weird problem of extremely disproportional down and up speeds in meshed environment.

Example:

  • I have 300/300 fiber uplink.
  • Archer C7 with openWRT as main router.
  • When connected over wifi to 5GHz AP on main router I can do 160/250MBit
    now the strange part...
  • I have 2 dumb meshed APs (Cudy X6)
  • when I connect to 5GHz AP on those APs I get 0,8/160MBit

Question is: What could be the reason for such tragic download speed? Upload is just fine and very much about what I would expect, but the down is pure tragedy. Where should I start investigating?

I was looking around but it seems that no one had such extreme difference between down and up.

2

Your 10 year old router (model) was designed with 50 MBit/s WAN connections in mind, you're just expecting too much from this hardware.

While you don't need to go quite that far for 300 MBit/s, you will still need a faster and more modern router for that.

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3

Well, not sure if you even read my post.

Archer C7 has 1GBit WAN port and it IS able to reach the 300MBit without any issues. Definitely it should be able to reach more than 0,8MBit :wink:

The problem here is not HW, it is some SW configuration and I am trying to find it out.

To me it seems to be the mesh configuration.

4

@shaman79 you can try to use fastroaming instead of mesh.
I have one config similar at yours (1 Router + 5 AP's in fastroaming) working fine (not at home, business use).

5

I use mesh as a backhaul - client APs are already set for 802.11r.

6

If you connect via SSH to one AP and try to run a speed test (iperf3 for example) the speed is correct?

7

I have a C7 (only C7 nodes) mesh that works - but its only 50-100Mbps on v22.

Mesh is better when carried out on the same chipset or router as a general rule of thumb.

The C7 is not a good match for the Cudy X6 by the looks of it.

Possible workarounds would be to....

  • create a 2 node Cudy X6 mesh - more likely to work.
  • on a mixed mesh try rolling back the wireless radio settings to see if it will connect: ie. 40Mhz channel instead of 80Mhz, etc..
  • If mesh is too much of a headache then go ap/sta instead. Ap/sta almost always works with mixed routers.
  • Use the Cudy X6 as your main router as it is newer and faster (?) than the C7.

Other things to try...

  • make sure all devices are using wpad-openssl and dnsmasq-full (I know this is recommended for C7 and probably Cudy X6 too - up to you to test)
  • make sure the C7 is using non-ct drivers.
  • retire the C7 to VLAN duty or dumb AP.

I used my old C7 for a VLAN edge router up until recently (replaced with a E8450 to match the new 1Gbps ISP connection). Also if I take a lightning strike hopefully it protects the more expensive equipment downstream. The C7 will do 700-800Mbps on v22 with software offload in my tests with a 1Gbps ISP connection. Still a great router with many possibilities. An N5105 mini PC I tested recently couldn't beat it at straight through routing.

8

It is getting even more weird...I am starting to think that something is haunted.

iperf is showing expected speeds, but wget is sloooow as hell. It seems that only http transfers are affected by the slowdown. The same wget when run directly from gateway runs OK.

this is showing results from one of the mesh points. iperf is ok between all devices, I cross tested all of them.

root@CudyX6:~# iperf3 -c a205.speedtest.wobcom.de
Connecting to host a205.speedtest.wobcom.de, port 5201
[  5] local 192.168.1.2 port 41876 connected to 62.176.246.197 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  4.93 MBytes  41.3 Mbits/sec    0    368 KBytes
[  5]   1.00-2.00   sec  8.76 MBytes  73.5 Mbits/sec    0    684 KBytes
[  5]   2.00-3.00   sec  9.88 MBytes  82.9 Mbits/sec    0    897 KBytes
[  5]   3.00-4.00   sec  9.45 MBytes  79.2 Mbits/sec    0    946 KBytes
[  5]   4.00-5.00   sec  10.0 MBytes  83.9 Mbits/sec    0    994 KBytes
[  5]   5.00-6.00   sec  11.4 MBytes  95.9 Mbits/sec    0    994 KBytes
[  5]   6.00-7.00   sec  10.1 MBytes  85.0 Mbits/sec    0    994 KBytes
[  5]   7.00-8.00   sec  12.1 MBytes   102 Mbits/sec    0    994 KBytes
[  5]   8.00-9.00   sec  10.1 MBytes  84.5 Mbits/sec    0   1.02 MBytes
[  5]   9.00-10.00  sec  10.4 MBytes  87.0 Mbits/sec    0   1.04 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  97.1 MBytes  81.5 Mbits/sec    0             sender
[  5]   0.00-10.08  sec  96.8 MBytes  80.5 Mbits/sec                  receiver

iperf Done.

root@CudyX6:~# wget -O /dev/null http://speedtest.newark.linode.com/100MB-newark.bin
Downloading 'http://speedtest.newark.linode.com/100MB-newark.bin'
Connecting to 50.116.57.237:80
Writing to '/dev/null'
/dev/null              0% |                               |   682k  1:19:27 ETA
9

For anyone stumbling here: I gave up.

The reason was probably that the mesh was cycling - the number of hops in the path was growing every minute. Also there were 00:00:00...hops on GW and I simply spent too much time trying to troubleshoot it already. There is not much information about the mesh internals to learn what could be the reasons.

To me it seems that mesh (802.11s and wpad-mesh-wolfssl) in OpenWRT is not yet fully working. I ended up with AP/STA in WDS mode.

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