Did you read release notes regarding the frame alignment thing? If you
didn't upgrade any 430 and 100 in the area, then you need to put the 450
frame alignment into legacy mode. It shouldn't cause that many issues
non-colocated, but since you're still seeing some DFS hits here and
there, that could be the issue.
And are you absolutely sure those APs could get sync over power before
the upgrade? That seems really odd to just lose that ability... unless
they changed something with power port pulse detection, which is
entirely possible.
On 1/24/2016 2:58 PM, Sean Heskett wrote:
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]
<mailto:[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
