Wireless Access

On controller running 6.5.3.3 the ARM rf-summary shows no free channels. On another controller running 6.4.4.16 I can see 18 free 5Ghz channels and 2 free 2.4Ghz channels.

#show ap arm rf-summary ap-name AAP-W******02

Channel Summary
---------------
channel retry phy-err mac-err noise util(Qual) cov-idx(Total) intf_idx(Total)
------- ----- ------- ------- ----- ---------- -------------- ---------------
36 0 0 0 93 8/7/0/0/90 0/0(0) 6/0//0/0(6)
40 0 0 0 93 11/0/1/0/90 0/0(0) 1/2//0/0(3)
44 0 0 0 93 11/0/1/0/90 0/0(0) 0/0//0/0(0)
48 0 0 0 93 19/8/1/0/90 0/0(0) 1/0//0/0(1)
52 3 0 0 93 2/0/0/0/91 6/0(6) 0/0//0/0(0)
56 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
60 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
64 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
100 0 0 0 93 0/0/0/0/91 0/0(0) 0/0//0/0(0)
104 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
108 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
112 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
116 0 0 0 93 9/0/0/0/91 0/0(0) 12/8//0/0(20)
120 0 0 0 93 9/0/0/0/91 5/0(5) 25/0//0/0(25)
124 0 0 0 93 9/0/0/0/91 0/0(0) 0/8//0/0(8)
128 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
132 0 0 0 93 0/0/0/0/91 0/0(0) 0/0//0/0(0)
136 0 0 0 93 9/0/0/0/91 0/0(0) 0/0//0/0(0)
140 0 0 0 96 0/0/0/0/91 6/0(6) 0/0//0/0(0)
1 0 0 0 89 0/0/0/0/85 0/0(0) 4/2//5/1(12)
6 7 0 6 94 11/9/0/0/89 0/0(0) 13/4//4/1(22)
11 0 0 0 90 79/66/1/6/88 4/0(4) 27/0//4/1(32)

Columns:util(Qual): ch-util/rx/tx/ext-ch-util/quality
Noise followed by "*" indicates that the last scan on this channel was a split-scan, which was
triggered by high channel noise. Check show ap arm split-scan-history.

HT/VHT Channel Summary
----------------------
Bandwidth Channel range Total interference index
--------- ------------- ------------------------
40MHz 116-120 45
40MHz 52-56 0
40MHz 100-104 0
40MHz 124-128 8
40MHz 36-40 9
40MHz 60-64 0
40MHz 108-112 0
40MHz 132-136 0
40MHz 44-48 1

Interface Name :wifi0
Current ARM Assignment :52+/18.0
Covered channels a/g :18/0
Free channels a/g :0/0
ARM Edge State :enable
Last check channel/pwr :6m:52s/5m:2s
Last change channel/pwr :13m:13s/15m:1s
Next Check channel/pwr :40s/2m:16s
Assignment Mode :Single Band

Interface Name :wifi1
Current ARM Assignment :6/9.0
Covered channels a/g :0/3
Free channels a/g :0/0
ARM Edge State :enable
Last check channel/pwr :6m:44s/46s
Last change channel/pwr :4h:9m:2s/4h:9m:2s
Next Check channel/pwr :1m:5s/5m:44s
Assignment Mode :Single Band

Is this a known issue in this code revision or someother problem?

That is a per-AP counter that determines how many channels have no APs on them as a possible destination.  It could vary depending on density and it potentially could be different for every AP on the same controller.

I understand that the values could vary between different APs depending on the RF environment. What I don't understand is why in this case when so many channels have an interference index of 0 and high quality they aren't being counted as free channels. Is this what you would expect?

It is possible that those channels have not been scanned enough times to determine that.

Have you seen the document here?  https://community.arubanetworks.com/aruba/attachments/aruba/unified-wired-wireless-access/7592/1/ARM%20Doc%20Supplement.pdf

It might not answer your question specifically, but it would give you an idea in general how ARM works.

@rossdrossd i also see the same, did you take this further and get it confirmed as a bug ?

@dugem2016 no I haven't progressed this. Colin's last suggestion was to wait longer but after 27 days the a/g free channels are still showing as 0/0. I'm less concerned as ARM has chosen sensible channels rather than them all being the same when I originally posted.

indeed too in my case arm is still choosing to move around when provoked to do so, but the free count should not be 0/0 as far as i can tell. 

What AP model is this and the regulatory domain set to for the AP? I've seen there where AP's haven't been supported in a regulatory domain.

Try the below to determine what channels are allowed in the country.

 show ap allowed-channels <country-code>

@zalion, I think it's something other than the regdomain - i tested this on ap215, ap315, ap92, ap135 in a domain that is a first level regdomain