AP PMP450 <-> SM PMP450 REGREQTOMAXERR and incorrect Air Delay


I'm having trouble with few (1-2 SMs) of a lot of 100 which they are not registering to the AP. They keep scanning, registering, scanning and so on.

Nothing is reported in the AP

But in the SM there are lots of messages with REGREQTOMAXERR and OOB

The messages are absolutly cryptic.. No way to understand what is happening. Checked everyting in both AP and SMs but they keep scanning/registering..

Finally I noticed something:

-On the AP the max range is SET to 5 miles. All SMs are between 1-3 miles.

-On the status page of the SM, while REGISTERING it seems it calculates the Airdelay distance and it says 5.01 Miles !! (real distance is 1.8 mies!!!).

So it may be the AP is dropping this OUT OF RANGE SM...

-Then I updated the Max.Range in AP to be 6 miles

-Now the SM while registering says distance is 6.03 miles and drops again !!!!

AP is 13.2.1

SMs are 13.2.1 (50%) and 13.1.3 (50%). This problematic SM is 13.1.3

May be this a software bug or something to fix or a defective SM?

Best regards


What is the environment of the area.  Are  there  working SM's relatively close to the affected SM's?  With the reported air delay I am wondering if possibly there is something in the way and possibly receiving the signal off reflections.  How is the signal strength compared to other SM's about the same distance from the AP?

I was thinking further on this issue.  Has the SM with the issue been replaced with another radio to see if the problem is still occuring?   This may help seperate if it is a real RF issue or possibly hardware or software issue.  Are you using a reflector or dish?


environment is very easy: SM at the roof. AP at ~ 3 Km and more than 500m above the town. Absolutely line of sight.

Yes there are SMs in the same street. The nearest is ~20m.

Signal strength is good (-55 -> -63) for all the SMs.

Yes if replaced with another SM it works like a treat.

All SMs have reflector.

We would like to look at this in more detail.  Could you open a ticket with CNUT captures?  http://www.cambiumnetworks.com/support either support-->"contact support "or "open  a support case"?