We are having an issue in a number of areas on our network where SM sessions will get “stuck” and the customer appears offline. When this occurs, customer traffic stops for the SM, the SM goes “offline” in cnMaestro, and you can’t access the SM directly or via the AP proxy. The fix is either to power-cycle the SM or on the AP, to go to tools → sessions and select the SM. Then drop the SM session. After this, the SM comes back online immediately and behaves normally for some time.
There is nothing useful at all in the logs of the AP or SM when this happens.
I don’t see anything in the 24.2.1 release notes that indicates this is an issue fixed there. Do any others experience this same behavior? Is this a known issue to Cambium?
What frequency and area of the US are you located? We are seeing similar behavior on 3ghz but power cycling doesn’t seem to fix it. The issue will just clear up all on its own. Sometimes in 15 minutes, sometimes in 2-3 hours. Preparing a full network downgrade to 22.1.2 overnight tonight to see if this has any impact.
These are all CBRS radios in my case as well. In my specific case the session doesn’t drop, the SM just won’t respond or pass traffic. It sounds like you are dropping sessions completely, which is usually related to interference in my experience.
I’ve traveled that road and the spectrum analysis only shows our own adjacent radios during these events. Nothing on the specific channel experiencing the issue. In regards to your issue, I just discovered today in the release notes for 24.2.1 there are issues with P11 SMs. Are any of your problem sessions on P11 hardware?
I just noticed this thread, I don’t think it has anything to do with 24.x FW. We’ve seen exactly this behavior as long as we’ve used 450 radios, all the way from FW versions 10.x to 24.x I believe. Both 3 and 5 GHz. 450, 450i, 450b, offhand I can’t say if we’ve seen it with 450m APs. I don’t remember if we saw this on FSK or 430 radios, I don’t think so, but we had fewer customers back then.
It doesn’t happen often but enough to be annoying. As you say, the SM is online in the AP sessions tab, but neither management nor customer data is passing. Just waiting doesn’t work, but as you say, resetting the session from the AP immediately corrects the problem. I hesitate to call this a stuck session because Cambium uses that term for a specific problem and I’m not sure this is it. I thought stuck sessions would fix themselves after a little time.
I keep thinking this will go away at some FW or HW version but it never does.
Now that we’ve updated the entire network to 24.2.2, we’ve started noticing this issue… it doesn’t happen often, but we’ve caught 3 different SM’s on two different AP’s now. PMP450m 3GHz + PMP450b.
One thing that we’ve noticed is that while the SM is in this “stuck” state, the rest of the SM’s across the AP will have poor latency/jitter and even packet loss, despite having great modulation. Kicking the stuck SM will fix this issue across the AP.