sudden disconnection of all SMs after connection of LHG HP elevate

GM forum,

on last week, i connect an elevated LHG HP on a 2000 AP, with 4.3.2 software, upgraded later with

AP was running 3.5.6

On next days, i experienced various freezes of radio part: on 30 clients, all disconnected but one or two. A reboot solve the situation and all clients come back.

Then i try to upgrade the AP to 4.3.2 . Same issue.

Also signals reported in teh AP wireless monitor dashboard was very strange: e.g 29/-74 (+ 29!!!)

Then I swap the LHG HP elevated with a SXT w/3.5.2 onboard, and no more freezes, all was back to normality. Downgrading the software of AP from 4.3.2 to 3.5.6 back to normal values also the RF signals displayed.

Any help on what happened? I have lot of LHG that i fear to elevate because freezes of the APs.

Regards and thanks in advance.


The incorrect RSSI value is a known problem. SMs with FW ver. 3.x.x and 4.x.x report this level differently to the AP. This is a cosmetic defect and not related to freezes which you see.

Try the latest beta 4.4-RC5. It is quite stable. Just make sure that AP and SMs all have the same FW version. Mixing firmware versions may give unexpected results and not recommended in the long run.

Hi Andrii,

TY for the reply. Signal difference IMHO is not only cosmetic, as i see that a -90/-74 SM SXT elevate with 4.4 and a lot of disconnection was rock stable -72/-72 after downgrade to 3.5.2, latest pre-4 release available.

But, move on on the problem. AP was upgraded to 4.3.2, via localhosted CNmaestro, as also the SMs. few units remain to 3.5.x because an "unknown platform" error on CNmaestro. A total mess. All radios but one or two offline, every 12-20 hours circa.

Reverting AP to 3.5.6 still freezes.

Only eliminating the two LHG elevated with 4.3.2 onboard AND reverting all SMs to 3.5.x (depending on platform, 3.5.2 for SXT and 3.5.6 for XM/XW) had the effect to re-stabilize the scenario.

I see the changelog of 4.4, maybe you in cambium have fixed some of those issues... but better maybe follow my old rule: never touch a running system :)

If you have suggestion, those are welcome. If can be useful for you, the AP log show me an error , i don't remember well... "IMA resources exausted" or similar. I had a log on a txt somewhere on my pc.. just hard to find it :)

TY again,


All radios need to be 3.5.6... or 4.4.1-RC5... NO MIXES! I would recommend you stay at 3.5.6 at the moment until 4.4.1 is done. It will hopefully fix many dropped session issues.