PoE advice

[JordanT91]

Hi all. I'm after some advice on PoE.

I currently don't have PoE switches (other than two old ones) but I'm in a situation now where we are purchasing a large amount of IP phones and CCTV cameras to be dotted around school in various buildings. I have been using midspan PoE injectors in my main cabinets and inline PoE injectors (one or two per smaller cabinet) but this is now not enough.

My switches are mainly HP 2920s and 2530s, non-PoE. Of course had I known 5 years ago what I know now, I would have spent the extra on PoE versions. I've been trying to purchase extra midspans for my smaller cabinets but I've been told they aren't really a thing anymore, and I can't seem to find them for sale anywhere. Apparently this is because PoE switches are now so much cheaper. My issue is, though, adding more switches into my network isn't really ideal. I can pick up 8 port PoE Ubiquiti or Netgear switches for a couple of hundred quid, but it's just introducing a difference set of protocols and ultimately it would be making my network more complex. What do you think I should do?

 

Network diagram

[robyholmes]

Ideally you need to replace or install one larger POE switch per cabinet. For example each cab would have a 24 port POE plus some non POE switches. Make can be any you like but hard to ignore the Unifi range due to the features and price.

[Davit2005]

Hi all. I'm after some advice on PoE.

I currently don't have PoE switches (other than two old ones) but I'm in a situation now where we are purchasing a large amount of IP phones and CCTV cameras to be dotted around school in various buildings. I have been using midspan PoE injectors in my main cabinets and inline PoE injectors (one or two per smaller cabinet) but this is now not enough.

My switches are mainly HP 2920s and 2530s, non-PoE. Of course had I known 5 years ago what I know now, I would have spent the extra on PoE versions. I've been trying to purchase extra midspans for my smaller cabinets but I've been told they aren't really a thing anymore, and I can't seem to find them for sale anywhere. Apparently this is because PoE switches are now so much cheaper. My issue is, though, adding more switches into my network isn't really ideal. I can pick up 8 port PoE Ubiquiti or Netgear switches for a couple of hundred quid, but it's just introducing a difference set of protocols and ultimately it would be making my network more complex. What do you think I should do?

 

Network diagram

 

It depends on the complexity or the network and any business case/need for high availability and redundancy.

 

If you have a flat network or minimal vlans then Unifi will suffice.

 

If you are doing anything fancy (internal OSPF, stacking, multiple spanning tree instances, etc) then you will find that Unifi cannot full fill these requirements as far as I can see.

 

When it comes to phones you will prob need features such as LLDP-MED etc on the switches, a lot of the HP/Aruba switches have this function, I can only think of the HP 2810 which is an older switch that doesn't.

 

You can get smaller midspan injectors with multiple ports still off amazon. I have these at home for specific purposes with 4port and 8port versions but it does not give the flexibility of just been able to plug a phone/AP/CCTV etc. into any live network point as a PoE switch does.

Edited June 12, 2020 by Davit2005

[geohanson]

I’m currently upgrading our switches, and we’ve stuck with Aruba/HP. I’ve used Netgear but much prefer the HP management interface (both web and CLI) and find it easier to use than the Netgear one.

 

I’ve just put a single HP 2930 PoE switch in each cab and the rest of the switches are non PoE.

 

Make sure that you work out the total wattage of all the PoE devices you’re going to connect to the switch. I think the 2530 PoE switches only supply 195w total whereas the 2930F supplies 370w. This might not be an issue for IP phones, but could be for lots of APs and cameras.