alright so after digging into this and making some adjustments I think i've
got the DFS events settled down now.
*1. Issue:* The 14.1.1 upgrade on PMP450 APs using the 5.4 band will
delete "Alternate Frequency Carrier 1" and "Alternate Frequency Carrier 2".
*Fix:* I had to log into each AP and manually add the 2 alternate
channels back into the APs. This way when we have a DFS event the AP will
move to another channel. Since the upgrade had deleted the 2 alternates
the AP would shutdown for 30min.
*2. Issue: *The tower that was having the most DFS issues has 11 PMP450 APs
and It's a commercial tower with a lot of FM stations etc. All APs are
connected to a CTM2 however after the upgrade half the APs were getting
sync from the CTM2 over the power port and half didn't see any sync on the
power port.
*Fix: *after reading other reports of the 450s having weird sync
issues (causing other issues besides DFS events) I decided to force all 11
APs to use the onboard GPS and I turned off the power port timing and
timing port timing to achieve this. So now all APs at this tower are
receiving sync from the onboard GPS.
*3. Issue:* Somewhere along the line (13.x) cambium made it so that a
450AP in the 5.4 band couldn't be set to more than 75% downlink. We
originally had them set for 85% downlink and they were timed with our 430
APs. Well when cambium forced the change without any notification suddenly
our 450 APs were out of time with our 430 APs. The area that this problem
tower is located we had removed all the 430 APs and moved them to smaller
towers at the edge of our network so I didn't think we'd have any timing
issues since there were mountains blocking the signals. However there was
one tower with 430s still on it that was ~7 miles from this problem tower.
*Fix:* I changed the 430 timing to match the 450 timing at the problem
tower.
after running this weekend with the new settings I've only had 1 DFS event
where as before these fixes the were a couple APs having DFS events 2-5
times a day.
In conclusion it seems like 14.1.1 is WAY more sensitive in regards to
timing sources. Also 14.1.1 doesn't seem to reliably receive sync over
power. Again when were were on 13.2.1 we didn't have any of these issues.
14.1.1 introduced some timing and DFS issues but they are somewhat
manageable (i really hate turning off a sync source because it'd be nice to
have it as a backup). It seems like if a nearby AP is out of sync that
will trigger a DFS event.
2 cents. I'll report again in a few days to see if these fixes have
eliminated the DFS events.
-Sean
On Wed, Jan 20, 2016 at 5:41 PM, Sean Heskett <[email protected]> wrote:
> I will be opening a ticket with cambium but I wanted to let everyone know
> this issues we just came across.
>
> I updated all our 450 APs to 14.1.1 yesterday. On our 5Ghz 450s we use
> the 5.4 band. On all these APs the "Alternate Frequency Carrier 1" and
> "Alternate Frequency Carrier 2" were reset to "none". when I go and set
> them back to what they should be, save and reboot they still come back as
> "none".
>
> Because of this if we experience a DFS event we have no other frequency to
> hop to.
>
> Additionally we have a couple APs that after the upgrade are now seeing
> DFS events when previously they experienced no events...ever. We live in
> the middle of the rocky mtns. so there really shouldn't be any events
> because of all the granite clouds in the way ;-)
>
> anyway, DFS seems to be broken on 14.1.1 and I wanted to let everyone know
> before they apply the upgrade incase you need DFS to work properly.
>
> -Sean
>
>
