Edge closet design

[DJaquays]

We’re getting ready to refresh a significant number of edge closets and are looking to change up a few things. Our primary goals are:

• Support 2.5/5gbps links for our WAPs.
• Reduce/eliminate total downtime of the wired network and wireless network
• Save money

The current thought is to do something like the following:

• Place 2 higher-end switches capable of multi-gigabit links to handle the WAPs (max ~20 APs/closet)
• Fill out the remaining port needs with lower-end PoE switches

The question is, what’s the best way to accomplish the first 3 points following the second two. My initial thought would be to take the two higher-end switches (either 5520s or x465s) and set them up as an MLAG and the lower-end switches (either x440s or v400s) as a “stack” (with the understanding that V400s don’t actually stack and assuming that V400s can be uplinked to an MLAG). This should allow any one of the 3 entities to go down for whatever reason (hopefully just firmware updates) without taking the other 2 down.

Diagram of what I think is a good idea until people tell me why I’m being dumb:

Am I missing anything? I understand that nothing benefits from the MLAG except for the stack and the uplink to the core. Is there a better way to accomplish what I’m after?

[DJaquays]

The short answer is: probably. We generally upgrade our networking equipment every 7-10-ish years. So we have to think about what the environment is going to look like in 5 years, when there’s been enough time for significant change in end user technology because we still have multiple years before the next refresh. We’re a medical school and healthcare facility, so we have some significant device-dense areas, bandwidth intense applications (VDI, Citrix, telehealth, virtual classrooms, remote lecturers, Netflix, spotify), and patient care critical devices (though we’re not a hospital, so not life/death level critical). Couple that with a significant group of endusers (students) who expect to walk in with the latest and greatest devices and have the best experience.

The spec sheet of the APs we’re moving to says this:

• P type: Indoor, dual radio, 5GHz and 2.4GHz 802.11ax 4x4 MIMO
• 5GHz radio: Four spatial stream Single User (SU) MIMO for up to 2.4Gbps wireless data rate with individual 4SS HE80 (or 2SS HE160) 802.11ax client devices, or with four 1SS or two 2SS HE80 802.11ax MU-MIMO capable client devices simultaneously
• 2.4GHz radio: Four spatial stream Single User (SU) MIMO for up to 1,150Mbps wireless data rate with individual 4SS HE40 802.11ax client devices or with two 2SS HE40 802.11ax MU-MIMO capable client devices simultaneously

That seems to indicate that you can exceed 1gbps by a lot with 2SS devices and 80MHz channels

[James_A]

Are your APs actually going to push more than 1Gbps? Most client devices are 2SS and don’t support MU-MIMO so even on a 40MHz channel the max data rate under 600Mbps. There is the argument for futureproofing for wifi 6E which will allow wider channels but that’s still a couple of years away and even then most environments aren’t going to exceed 1Gbps per AP IMHO. If you do have environments running 80MHz channels with 3SS clients then it’s possible, but it’s by no means the general case.

[DJaquays]

Yeah, my concern was specifically around making sure the switch design (mlag ↔ mlag ↔ stack) would work and that there wasn’t a better/different way to accomplish what I think we want to. The APs will be HPE/Aruba 500 series, which have 2 ethernet ports that can be configured as an LACP group, but in most of our environment, it’s not really worth the added overhead to build it out that way, especially since we don't have the structured cabling to support that today.

[StephanH]

Here is a small update:

The GTAC confirms the different statements in the documents and will clarify them with the product management.
 

[StephanH]

Strange indeed,

in addition on the product page:

https://www.extremenetworks.com/product/ap510ie/

There is a hint regarding redundant poe (search for redundant on the web page).

I have opened a GTAC case and will write here what comes out of it.