ePMP 3000/4500 Compatibility

Hi. I just wanted some clarification on what the compatibility is (or plans are) for AX with previous generations. Specifically whether 4525s can connect to a 3000 AP with everything running 5.8 or 5.9 firmware?

I realize that we can change AP’s out to 4500’s, and use a 4500 AP with the existing 300-25 SMs we have in the field, but is that going to work the other way around? In other words - can we just go ahead and purchase 4525 and use them on our 4000 & 3000 series sectors?

The short answer to your question is, no.

Here are the details for e4k’s backwards compatibility mode:

  • Introduced in firmware release 5.7.
  • Interoperable between 5.7 and all newer firmware revisions.
  • Only available in TDD PtMP and PtP modes (not available for WLR or ePTP).
  • Only works with e3k AC clients to talk to e4k AP’s.
  • There’s no forwards compatibility, e.g. an F4525 can’t talk to an e3k AP.
  • There’s no BC mode with e1k/e2k/elevate 802.11n-based radios.
  • Firmware 5.8 adds support for e1k/e2k 802.11n-based radios, however there is no BC with e4k AP’s.

Here are some deployment examples:

e1k/e2k/e3k AP’s and SM’s running 5.x can all talk to each other… but only the e3k SM’s will be able to talk to an e4k AP.

e3k SM’s running 5.x can talk to an e4k AP running 5.x.

I believe, but need confirmation, that an e3k SM running 5.x can talk to an e3k AP running 4.x.

I believe, but need confirmation, that an e3k SM running 4.x can talk to an e3k AP running 5.x.

e3k SM’s running 4.x can not talk to an e4k AP running 5.x.

I have not validated if an e3k slave running 5.x can connect to an e4k master in TDD PtP mode. The GUI seems to imply that this configuration is supported.

Ok - thanks for the reply Eric. Great and detailed answer as usual. :+1: That’s what I thought… that a F4525 can’t talk to a 3000 AP. That seems such a strange decision. I would start purchasing 4525’s for most situations, if they could talk to our existing APs, but this pretty much forces me to keep buying older technology, until I can upgrade all the APs. And then if folks are going to have to upgrade their APs first, then that kinda gives them the decision to upgrade to whatever they want.

Anyway, thank you very much Eric. I had purchased 24 Force 4525s, but I’ll see if I can send them back.

What are you trying to replace on the AP side? An e3k 4x4 or 2x2? If you’re just replacing a 2x2 AP, then the 4500L will work perfectly for this and you’ll get the same performance you’re getting out of the e3k with your legacy AC SM’s.

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Yes - we have replaced some 3000L’s with 4000L’s and that is (sort of) a solution.

The problem is:

  1. That policy means we have to do that on all sectors FIRST before we can add 4525 SM’s – I’m just saying I think that’s a strange decision for Cambium to make. It would have been MUCH more convenient to have working 3000/4000 compatibility both ways, so that 4525’s SM’s would be compatible with 3000 APs.Then we could have gone ahead today and started buying and adding 4525’s to our existing 3000s, which would mean we could move to the AX generation much more quickly - without having to upgrade every Sector first.

  2. On the sectors we have done that on, we are generally seeing a loss of 3-5 dB typically, and a lower modulation resulting. So, in several examples, we see a 3000L with a 300-25sm getting DS9 modulations, and when we put up a 4000L and the same Cambium sector, and see the client drop by 3-4-5 dB and now modulate at a DS7 instead.

Example: The latest client we upgraded was a -59 on the 3000L/300-25 and he’s now a -64 on the 4000L/4525

I should say - I’m generally very pleased with the 4500/4525’s and their potential. It’s an exciting time again. I’m just disappointed in the business decisions Cambium makes which limit our options. We’re a small company and replacing 60 APs is a LOT of time & money. It’s mainly the time though - so it would have been great to have the same upgrade path we had when the 2000 was introduced, and then when the 3000 was introduced… we could start buying 300-25’s right away, and use them everywhere on any AP… and then upgrade the AP’s as time allowed.

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Hi @ninedd

I agree with you

I have a question for you:

What AX model are you using in your 2x2 or 4x4 APs? What reference are you using, the 4500L?

Why not use 4x4?

Why not use 8x8?

Has the reduction in modulation in AX seen a decrease in the speed it supplies?

Could it be that the received power is related to the maximum power your SMs have in AX?

Have you seen improvement in your links using AX?

I’ll give you an example… I started migrating trunks from force300csm to force400c and the results were not good, since force400c works in the same contaminated spectrum as force300csm… so we had to move to force4600c. We are just in the trunk process. How do your PtMP links work in AX?