Yuck. 3.6 does the same kind of stuff. If a sector reboots, it can cause
an LBT hit. It'll boot up and not quite be on the correct timing.
Usually fine after a few seconds. Known issue though. DFS is different
with the 30 minute timeout. THAT really sucks.
I have faith in the software guys though. They'll get the stack dumps
and resets figured out. Because I'm sure they're really tired of hearing
us bitch about it already. :)
On 1/26/2016 6:27 PM, Sean Heskett wrote:
yeah I saw the notes about the frame alignment. I set them all to "on
mode1" which didn't seem to help.
after watching this for a couple more days it seems like what is
happening is one AP on the tower will have a stack dump which causes
other APs on the tower to register a DFS hit.
then sometimes the DFS hit causes a stack dump in that AP.
14.1.1 has a lot of speed improvements but all the DFS hits that are
now happening that didn't happen on 13.2.1 are causing issues.
-Sean
On Sun, Jan 24, 2016 at 5:02 PM, George Skorup <[email protected]
<mailto:[email protected]>> wrote:
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
