NanoStations M5 : frenquency changes suddently ?!?
we have set up for 2 years now a PtMP network using 4 NanoStation M5.
Last week we discovered that one of the APs did not respond and decided to monitor this network using a CRM POINT. Doing that, we discovered that the CPE changes sometimes its frequency without any reason !
Normal situation : frequency is set on all APs to 5580 MHz.
Normal status in CRM POINT :
And suddently CPE frequency is changing :
What we can see in the log of CPE :
Jun 3 10:56:21 wireless: ath0 Radar found on channel 116 (5580 MHz) Jun 3 10:56:21 wireless: ath0 Changing to channel 131 (5655 MHz) Jun 3 10:57:13 wireless: ath0 STA-TRAFFIC-STAT mac=dc:9f:db:40:2b:22 rx_packets=23300 rx_bytes=7569164 tx_packets=52893 tx_bytes=4079348 Jun 3 10:57:13 wireless: ath0 Expired node:DC:9F:DB:40:2B:22 Jun 3 10:57:13 wireless: ath0 STA-TRAFFIC-STAT mac=24:a4:3c:0c:bb:15 rx_packets=199575 rx_bytes=24680974 tx_packets=296837 tx_bytes=299148107 Jun 3 10:57:13 wireless: ath0 Expired node:24:A4:3C:0C:BB:15
All APs in 5.6.6 FW since 2 days.
Any idea to avoid this channel shifting ?
You are running a DFS channel, which means that it MUST detect radar, and then either switch channels, OR turn off for a defined number of minutes !
TO eliminate it turning off for a defined number of minutes, you can select a couple of alternative channels for it to turn to, and it will do so, without taking your customers off the air.
You have what is called a "Scan list" on both the AP, and the Stations. You need to Enable it and put in 2-3 channels in it. First, the one that you are currently using 5580, and two differnet ones, say 5560 and 5570.
The "Scan Lists" MUST be the same in both the AP and the Stations (CPE's) !
This way YOU get to decide where the radio switches to, and not the radio !