Media Converter/PoE injector for MR86

[gcarmich]

I'm working on a WiFi design using MR86s on to cover a train platform.

The platform is 320m x 20m.

With the PoE distance limitation, I'm considering using media converters with PoE injectors to increase the distance between the switch and the AP.

Is there a recommended 2.5G media converter with PoE for the MR86?  Preferably one that is ruggedized?

Is there a reason that Meraki doesn't directly support SFPs and AC power on their APs?

[alemabrahao · Accepted solution]

https://documentation.meraki.com/MR/MR_Overview_and_Specifications/MR86_Datasheet

[PhilipDAth]

I wouldn't worry about getting a 2.5Ghz PoE injector.  You are unlikely to see any additional performance.

Many of the APs support AC power input.  Adding an SFP port would add a lot of cost that 99.9% of customers would not need.

Any chance you could use something like an MS120-8LP instead part way along, to extend the distance, and feed several APs from it?

https://meraki.cisco.com/product/switches/access-switches/ms120-8/ 

Personally, if it has to go "in the open" I would install it into a little vandal-proof electrical enclosure (such as an IK10 rating).

[gcarmich]

PhilipDAth -  Won't the MA-INJ-6: Meraki MR MultiGigabit 802.3bt Injector power both 2.4 and 5Ghz?

The layout will be very linear - basically APs all in-a-line above the track. The only common point will be in the center which will be well over 100m from the ends.  The APs will be mounted high so vandalism shouldn't be too much of an issue but it is something good to consider. Thank you

[PhilipDAth]

It would power both 2.4Ghz and 5Ghz - but you could use the cheaper model that is only Gigabit.

You can't use a PoE injector to extend the maximum range of Ethernet (which is 100m).  If the overall length of the Ethernet is over 100m with a PoE injector in the middle, you are likely to run into reliability problems (or it won't work at all).

You need to use something that re-generates the frame, such as a switch or a media converter.

[gcarmich]

Thanks.  The idea would be to collocate fiber termination and AC power near the AP and just use a short run of Ethernet between the two.  That way we get to spread out the APs in a long line.

[gcarmich]

I've been looking at the MA-INJ-6 in closer detail.  

I was thinking that the MA-INJ-6 was a PoE/Media Converter combined (took in fiber (for Data) and AC (for power) and put out PoE to the AP) but I now realize it is a only a 10G Power Injector.

It appears to 10GBASE-T (copper) input and output - no fiber/SFP support - correct?

Isn't 10GBASE-T (copper) limited to 100m like PoE?

If I wanted to run fiber and AC power in the same conduit to the AP, could I use a "copper to fiber media converter" like this -

S-10GT-XFPH Media Converter 10GBase-T to XFP Copper and Fiber Converter (https://www.perle.com/products/media-converters/10gbase-t-standalone-rate-converter.shtml?_gl=1*1sn2...)

and the 

MA-INJ-6 power injector to power the AP and provide backhaul over longer distances (>100m)?

[PhilipDAth]

Correct, it is only a PoE injector.  No fibre.

The media converter you linked looks like it would do the job to me.

If you could run a fibre to a central location and then run 2 or 3 APs copper cabled back to that location, an MS120-8LP will likely give a better solution (and involved a lot less parts).  It just doesn't stack up so well if you can only cable a single AP back to where the fibre would terminate.

[gcarmich]

The area to cover with WiFi is long and thin. I'll take another look at the MS120-8LP and see how it might fit in.  Thx