Affected platforms: ePMP4500s Affected versions: 5.10.0 and newer
Backward Compatibility in ePMP 5.10.0 and Migration Mode Overview
Starting with the ePMP 5.10.0 release, backward compatibility has been introduced between ePMP 4500 series Access Points (APs) and legacy Subscriber Modules (SMs) such as the ePMP 1000s, Force 180s (F180), Force 190s (F190), and Force 200s (F200). This functionality allows network operators to continue supporting older SMs while upgrading APs infrastructure.
To enable this feature, navigate to the Configuration → Radio section of the web user interface and activate Migration Mode.
Migration Mode is specifically designed to support legacy SMs—including F300, F180, F200, and ePMP 1000—during transitional periods. While this mode facilitates smoother upgrades and minimizes service disruption, it is intended strictly for temporary use during network migration. It is not recommended for long-term deployment due to performance trade-offs.
Increased Latency: Users may experience higher latency compared to standard (greenfield) deployments.
Reduced Throughput: A slight decrease in data throughput may occur.
Performance Variability: Overall sector performance is influenced by both the quantity and proportion of legacy SMs (F180, F200, ePMP 1000) connected to the AP.
To achieve optimal performance, it is recommended to complete the migration to newer SM models as soon as feasible.
lets be honest here, many of us are not going to forklift
If replacing 1k/2k APs, Can we assume we will see density improvements at minimum?
If replacing 3k will we see improvements?
Overall sector performance limitations I assume are in reference to a full 4k deployment? Is this accurate, and we will likely see reliabilty/performance improvements in reference to 1/2/3k deployments?
How long will migration mode be supported? is it a scheduled firmware depretiated feature?
I would like to also ask this:
If no other changes are made to a legacy system, will replacing a 1k or 2k AP with a 4500 result in better performance than the 1k or 2k AP supported?
Indeed Cambium could provide little more details for this backward compatibility. We only recently exchanged lots of SMs to F300, since 4000 series wasn’t finished for two+ years and way too expensive for our market. Also absence of smaller form factor SMs didn’t help either, because absolute majority of our deployments are sub-3km, therefore F4525 was an overkill + many mountings would have needed to be replaced to support them. We also replaced almost all of APs from 3000L to 3000 4x4 during recent promotion, targeting to have all SMs F300 only on 3000 APs. The plan was to replace most busy APs to 4000 later and run them with F300 by replacing to 4000-series SMs for heavy users first when they becom available in Q2-Q3.
We found that forklifting is more expensive sometimes than the SM itself. People here don’t want to hear about it anymore unfortunately
While we don’t have many 130/180/200 SMs, there are still quite many Elevated Mikrotik SXT SMs. It’s a pitty to change them to AC/AX when they only use up to 10GB/week and perform surprisingly well. I wonder if there are any difference to run elevated Mikrotik 11n devices in comparison to F180s besides Licensing mechanism of course. It would be very nice if Cambium just droped the licensing and let say at least up to 10-15 elevated units to connect to 4500 APs. This would make lots of room for everyone to maneuver. Think of LTE compatibility - when very old Cat4 devices work in brand new 4-5G networks perfectly just with reduced capacity
@Fedor I agree with @squirrely. Cambium needs to provide more info on the performance hits of backwards compatibility. We have a LOT of ePMP3000 subscribers and a shortage of clean 5GHz spectrum so this information is essential for WISPS to migrate to the newer platform.
I have 2000, 3000 and 4000 sectors in my network. So far the 3000 performs the best. The 4000 sectors have great potential but over 10 subs the performance is dismal. I have 60 subs on 3000 with mixed 3000 and 2000 devices and actually a few elevated Ubnt devices too. I have no issues of major importance with the 3000 sectors. The 4000 sectors drop customers and reboot themselves every day. I think there are memory leaks in the software and other bugs. Please test more Cambium and try a memory leak detector tool. They have been around for 20 years!!!
did you have a chance to raise a support ticket for reboots and disconnects?
If yes, please let me know it’s ID.
ePMP AX platform is maturing with each new SW release. We have implemented multiple stability and performance improvement in the release 5.10.1.
If you still see issues on 5.10.1, it can be something environment specific and we would like to fix it especially for you
Unfortunately, they have decided not to have compatibility with connecting 4000 series SM’s (4518/4525) to 3000 series AP’s. So, even if you have a perfectly working, perfectly stable AP, you HAVE to change it out to a 4500 if you want to start loading 4518/4525 into that area.
And now there is EVO coming, and they kept saying ‘saving your previous investment’ but given what they’ve done with dropping 45xx SM compatibility, I would assume it’ll be the same with EVO. Even if we replace all our 3000 AP’s with 4500’s now - Cambium will need us to replace them again in Q1 2027 if we want to load the next generation 802.11be SM’s onto our AP’s
So we feel stuck - doesn’t really make sense to buy Force 300’s because that’s last generation, but can’t really connect Force 45xx without upgrading every AP’s first. And makes also almost no sense to go de-install a Force 300 somewhere during a 4000 upgrade, and then go re-install it for someone else on a 3000 AP somewhere… the truck rolls will really add up.
Anyway - to your question, you should be able to connect your Force 300 & Force 45xx SM’s to a 4500 AP and it should just work. If there’s incompatibility, Cambium will want to work that out, and they’ve been pretty good about that.
Well, I said numerous times. I don’t use 4000 APs yet and I’m not buying 4518s unfortunately. But I would if they’ve connected to 3000 APs. Just like F300 SMs connected to 2000 APs back then.. Each of us have its own considerations.
Sorry - my mistake, my reply above was actually intended for @rdsoutar’s post, but I see I accidently ‘reply to’ on your post instead. My mixup, sorry. @rdsoutar was saying that they were finding performance of their 3000’s the best overall, and have been finding the 4500’s more problematic… and so I was replying “yes, plus since there’s no compatibility for 4518/4525 SM’s on 3000 APs, that leaves in a similar situation, and leave us kinda in limbo”.
I’d also like to keep my 3000s until 4500 APs are more mature. But I really really do not like to deploy F300s when F4518 is available for similar price
Exactly - we feel stuck too. I’d be buying 100% just ePMP 4525/4518 SMs if they were compatible with our existing ePMP APs.
And the fact is, if we all need to change all our APs every generation due to lack of compatibility, then we all may decide to change to something other than Cambium.
4500 8x8 with over 40 F4525L on an 80 MHz channel, uptime lasting from one firmware update to the next. No client disconnections. The only issue is that pings/jitter/tcp speedtest behave worse under saturation once the load goes above 30 clients.
the promotions that are still available are excellent,
if you are outside the US, take advantage of the cheap dollar right now,
most importantly for me – Cambium knocks out the competition in terms of quality. UBNT has killed LTU, of which we still have quite a lot in our network; it was (and is) a good system, but you can no longer buy it in reasonable quantities, and the software has been dead for two years. At this moment, Cambium is the last one still standing after a heavy fight in the WISP and PtMP world.**
Looks like I’ll have to believe you 2jarek I’ll be ordering few APs and SMs to check how it works in select areas. Then will decide if to upgrade other APs.
But still it’d be nice to have forward compatibility of 4000-series SMs with 3000 APs, at least with some separate firmware on SMs. Because I’ll not be in a hurry to replace APs with 5-10 clients in some distant areas where 3000 still serves them perfectly.
