Powering Meraki APs

[BlackTie]

Greetings all,

 

I'm currently looking at getting some Cisco / Meraki APs and am currently working through the practicalities of installing them.

 

Does anyone have any experience of powering them from rack-mounted POE injectors? Are passive ones likely to suffice?

 

Thanks,

 

Steve

[TheRobins]

Hi Steve

 

Is it a cost reason you are not looking at a dedicated POE switch?

 

The cheaper ones I have seen to be not very useful, If you are talking sort of 8+ AP's the cost effective way is to go for a dedicate POE switch

[BlackTie]

I must confess - yes it is. We've enough switch capacity (in most places) but don't have POE switches - so a £50 8 port passive injector seems more cost effective than having to buy the equivalent managed POE switch..?

Or might I be spoiling the ship for a ha'p'orth of tar..?

[NB9457]

I've used rack PoE injectors in the past, no frills, does what is says on the tin and a massive saving!

[BlackTie]

Thanks - can you just to confirm you're talking about passive injectors (as opposed to active ones which seem almost as expensive as a POE switch!)?

Was this with Meraki APs, BTW?

Ta,

Steve

[Arreks]

We've got a dedicated POE switch for about 8 of our Meraki APs, and then we've got a few injectors for a few more APs - we're planning on getting another 8 or so more Meraki APs though so we'll probably get a new POE switch rather than more injectors just because it's easier to manage.

[localzuk]

Not sure what you mean by "passive" and "active" injectors. As far as I can tell, an injector is an injector. The difference comes from which standards they support. The only "Passive" ones appear to be a proprietary thing and don't mention the specific PoE standards in place.

 

Meraki AP's use 802.3at and 802.3af, depending on the model (the MR34 is 802.3at, MR18/26/32/66/72 all use 802.3af). So, whatever PoE injectors you use, they need to comply with the relevant standard.

[Wave9_Matt]

What you are referring to are called 'midspan injectors'. I've known them be used in a few networks, particularly for integrating AP's in to an existing network. The key considerations are, as Localzuk points out, standards compliance and making sure the PoE standard is correct for the equipment you use. Other factors are the introduction of an unmanaged device into your network and cost. If you are aggregating a quite a few AP's back into individual wiring closets / cabinets then midspans can start to look cost competitive with PoE switches.

[BlackTie]

Thanks for your thoughts. I had in mind something like these: PoE Products | WiFi Texas which as I understand it simply put 48V across the appropriate pair(s) in the cable, rather than negotiating the power requirements with the device.

[localzuk]

I'd hazard a guess that such a device, that breaks the various PoE standards, would void your connected device warranties. I'd not want something like that anywhere near our equipment. Considering the cost of wireless APs, you're setting yourself up for a potentially expensive loss if it goes wrong.

[BlackTie]

Fair point - although our vendor has suggested that this might be an option.

As ever it's a matter of balancing risk vs. cost...