I've got a small island about 1x2 miles with four CPE510s in AP mode in a central location and 6-12 clients on each one.  They are set to different channels (36, 40, 44, 48) with 20MHz bandwidth, are a mix of V1 and V2 hardware, and usually work pretty well.

 

Lately, the upload speeds have gone to essentially zero on some or many of the client nodes.  Replacing them seems to make things better for a while, but not very reliably, and then they get slow again.  [This may be a red herring, and swapping client nodes is non-trivial...]

 

Using iperf on an example uplink shows: (marco is an iperf server at the central location)

 

./iperf3 -fm -c marco.ian.pinecay.net --time 10

Connecting to host marco.ian.pinecay.net, port 5201

[  6] local 192.168.211.99 port 53420 connected to 192.168.200.11 port 5201

[ ID] Interval           Transfer     Bandwidth

[  6]   0.00-1.00   sec   130 KBytes  1.06 Mbits/sec                  

[  6]   1.00-2.00   sec  2.80 KBytes  0.02 Mbits/sec                  

[  6]   2.00-3.00   sec  0.00 Bytes  0.00 Mbits/sec                  

[  6]   3.00-4.00   sec  7.83 KBytes  0.06 Mbits/sec                  

[  6]   4.00-5.00   sec  0.00 Bytes  0.00 Mbits/sec                  

[  6]   5.00-6.00   sec  9.90 KBytes  0.08 Mbits/sec                  

[  6]   6.00-7.00   sec  33.9 KBytes  0.28 Mbits/sec                  

[  6]   7.00-8.00   sec  0.00 Bytes  0.00 Mbits/sec                  

[  6]   8.00-9.00   sec  4.24 KBytes  0.03 Mbits/sec                  

[  6]   9.00-10.00  sec  0.00 Bytes  0.00 Mbits/sec                  

- - - - - - - - - - - - - - - - - - - - - - - - -

[ ID] Interval           Transfer     Bandwidth

[  6]   0.00-10.00  sec   189 KBytes  0.15 Mbits/sec                  sender

[  6]   0.00-10.00  sec  60.8 KBytes  0.05 Mbits/sec                  receiver

 

Running iperf on another machine on the central LAN gets around 95 megabits, as most of our infrastructure is 100BaseT, so it's not an issue with the 'marco' server.

 

CPU Usage is low, memory is at 60%, SNR is 36 dB, MaxStream is enabled on the APs and set to Auto Adjust on the clients. Maximum distance is 1.5Km, so I've set it to 2KM.

 

All nodes are running the latest firmware (2.1.6 for the V1 nodes and 2.1.11 for the V2 nodes).

 

How do I further diagnose this problem, and find a solution?

 

Many Thanks!