MS130 switch installation - more Meraki Magic!

[jbright]

I fired up a new Meraki MS130-24X switch last night on our office network and connected five CW9166 APs to the multigigabit ports on it and they are all running at 2.5 gigabits now. Two of the connections are over 21 year old CAT5E cabling and the other three are running on much newer CAT6 cabling. None of the cabling runs are over 20 meters, but it's great that that old cabling still works so well. I didn’t have to make any changes to the wiring or the equipment, it just worked right out of the box with zero errors on any of the switch ports so far. Another awesome revelation is that the MS130-24X switch provides 802.3bt PoE support. Here's a screenshot from the switch that shows this:

Very cool!

[KarstenI]

How would you describe the fan noise of this device? 

[jbright]

Switch fans start out at full power on startup and then quickly idle back to a low buzz. Maybe a little lower than some of the other MS series 24 port switches that I have installed.

[KarstenI]

Thanks, it seems that this could be a great basement switch.

[PhilipDAth]

Wahoo!  Thanks for sharing.

[Brennan_Martin]

Hey @jbright ! Brennan here from the Meraki Switching PM team 👋. I’m so glad you’re enjoying the new MS130! I wanted to point out that, while the PoE chipset is indeed capable of understanding 802.3bt negotiation, it is still only capable of providing 30W of power like 802.3at. What you’re seeing in Dashboard is a slightly confusing use of terminology - where it says “advertised” what it should say is that the “PD requested” 60W BT. We’re planning on changing the terminology in the near future to be more clear. Sorry if I’ve burst any bubbles!

[jbright]

That's ok. If you send me an MS390 to test, we can call it even 😁

[KarstenI]

And I was already jubilating ... 

[peterk1]

Um, under what circumstances is 802.3bt limited to 30 watts? Sounds like 802.3at standard not bt which is 60-90W?

[KarstenI]

It is not 802.3bt that is limited. It's the switch that is limited in this way.

802.3bt is flexible in what can be provided by the switch. Class 4 bt is still 30W on the PSE.

[JCNOLA]

I just noticed this on the datasheet. stating 802.3bt and not actually providing 802.3bt power is a very big deal and not something to plan to change. It should be changed imediately or some people will not double check and order the wrong switches. the datasheet needs to be more specific, just like your post.

thanks for posting this valuable info!!

[cmr]

@Brennan_Martin if a CW9166 is connected to an MS130X where bt is understood, will the USB port work? 

The CW9166 connected to my MS130-12X is only using 12.8W, so there is plenty spare to give a USB device up to the 4.5W mentioned in the datasheet...

[Brennan_Martin]

Hey @cmr, you may want to confirm this with an Catalyst wireless expert (which I am not), but I believe the 9166 is looking for the PSE to agree to the availability of over 30W, and the MS130 will not do that. 

[cmr]

@Brennan_Martin there's definitely a bug in the dashboard, the BT requested power of 60W is used to calculate the power budget on the power tab of the switch.  So if you connected 4x CW9166, you would have no power budget left, even though the switch could only deliver a max of 120W out of its 240W budget.

That, at least, needs fixing!

[Brennan_Martin]

Sort of; MS switches don't actually reserve the requested power, and will allow oversubscription. So the switch will continue to provide power up to the actual available budget in use regardless. This is different than catalyst based and -M switches which will reserve the requested budget. 

[cmr]

Thanks for confirming, however it is still misleading as even at worst (which we plan for) the switch would never supply that, so the total is falsely inflated.  And unless you have 16.7.1 with an MS130X then it is an actual limit! 😉

[TyShawn]

@Brennan_Martin Thanks for responding to this post, but like others have stated limiting the ports to 30W and marketing them as BT switches (even if it understands BT) feels a little less than premium, or not being honest with the customer. Cisco / Meraki has multiple APs that require more than 30W of power and if the admins pair those APs with this switch then that admin will not get the full function of that AP. 

[Brennan_Martin]

Hi @TyShawn , I understand what you're saying; but know that we haven't limited the ports to 30W - that is all that the PoE chip is capable of providing. The intent was not to market the switch as BT to imply that more than 30W is available. Originally our datasheets only indicated the power budget in Watts. However, as this confusion arose, we've added some details to the datasheets to try to clarify that confusion. I agree that we may not have accomplished that clarity yet. For context, the PoE chip in the 130 models was chosen based on supply chain constraints when we were sourcing the components to ensure that we would have enough to build an adequate supply.

Thanks for the feedback - we'll see what we can do to set better expectations. 

[Sith00]

Thank you for some clarifications around this. 

So to sum it up, the bt standard in this case is used to achieve

mgig support

poe over 4 wires?

Still 30w on port and 25.5 for the PD?