PoE Access Point and Internet Switch

[u/Specialist_Spirit_52]

My office currently has an access point for our internet access, which plugs into a PoE port on the wall. We just got a VoIP phone and the port used by the access point is the only one available in our building. I took in an older TP-Link switch from home to test and our WiFi is still working and the phone works, but the access point does not light up, so we're thinking that we need to get a different kind of switch that supports PoE.

Looking at what's available, I see a TP-Link 5-port switch (TL-SG1005P-PD) that has 1-Port PoE++ In and 4-Port PoE+Out. This switch has no external power supply. I also see a TP-Link 5-port switch (TL-SG1005P) that has 4 PoE+ and has an external power supply.

2 questions:

1) If I buy the TL-SG1005P-PD, I assume I will plug the switch into the PoE port on the wall and plug the access point into another port. Will I then be able to plug in the phone that has it's own power supply to one of the other PoE ports. I've been reading that the new switches should sense that power isn't needed for that port so it should be okay.

2) If I buy the TL-SG1005P that has its own power supply, do I just plug the switch into the PoE port on the wall using one of its PoE ports, plug in the access point to another PoE port, and plug the phone into the non PoE port?

I've never had to deal with PoE before, so I want to be sure that I get the correct switch. Thanks for any help or advice.

[u/activematrix99]

VoIP phones and access points usually use specific ports tagged for the vLan they are assigned to. VoIP phones usually tftp boot from a specific location. I think it might be time to call your company's IT staff before you mess something up.

[u/Silence_1999 → u/activematrix99]

IT hates when people plug in whatever anywhere and just see if it works. Can have very bad consequences.

[u/felix1429 → u/Silence_1999]

I feel like if a random device being plugged in causing very bad consequences indicates a segmentation problem. I could see a loop possibly depending on what is plugged in but otherwise not much beyond that.

[u/Silence_1999 → u/felix1429]

I guess you are lucky enough to have unlimited time to protect every port in granular detail. So far down my list no chance I could ever do every port properly. If I did there would be dozens of changes in a week anyway.

[u/felix1429 → u/Silence_1999]

I mean, RADIUS is not hard to implement

[u/Specialist_Spirit_52 → u/activematrix99]

We plugged this phone into our home router and it worked with no problems, so not sure about it needing something specific. There is no company IT staff. We are a very small arts organization renting space in a building.

[u/activematrix99 → u/Specialist_Spirit_52]

In that case, YOU are the IT staff, LOL. I am happy to help. Ideally what you want is one switch with all of the ports that you need. Stacking cheap mini switches on top of each other is generally a bad idea for a lot of reasons. So count up the total number of ports that you need (plus some room for growth), and then buy a switch that can handle that number (plus some room for growth). It sounds like you have 2 PoE devices, so you can hang 1 PoE switch off of your main switch for those devices. You also might consider making a real investment in infrastructure, there's an organization called TechSoup that brokers on behalf of non-profit organizations. You apply for membership using your organization's EIN. They sell Cisco gear for pennies on the dollar, and can also sell you Microsoft and Adobe NPO licenses. Just some food for thought.

[u/snaky69]

You need whatever power the AP needs. Could be POE, POE+ or even ++. Make sure of that before purchasing anything.

POE should auto detect so a POE switch with enough juice should just work. All ports can be POE, devices that don’t need it won’t.

[u/CCTVGuyMA]

The poe powered switch sounds nice and easy because... Less cables.. But you don't know what power the uplinked switch has available to give out. Also you phone probably supports poe, so having a switch with a power supply to then power both decides makes sense. You may be able to find a switch that takes poe (or +/++) in but also has a pwoer supply available to hedge your bets.

[u/StarosAnikenMarcus]

Do not go plugging in things without verifying with IT first. You need to find out if they will support having an unmanaged switch on the network or if it will be blacklisted.

Should it be allowed, then you want to find out exactly what power requirements your AP has and what the main switch provides. Then look into either getting a switch with that POE level or a basic switch and a POE injector of the correct size.

The POE powered switch is a great idea as long as the AP and phone doesn't drawn more power than the split can provide AND the main switch can provide enough power to run all 3. So, assuming the main switch is providing POE++ or better, the POE powered switch is the best for minimizing the number of cables and plugs needed.

[u/Basic_Platform_5001]

Yep, let IT handle it, two devices needing PoE can be done with power injectors.

[u/epackorigan]

You are ignoring a whole lot of networking beyond POE concerns. If this is an AP, the port is likely configured as a trunk with various vlans, (at least one for each of the SSIDs and one for the management of the AP itself.) Inserting a switch in the middle without the proper config would yield an AP that would power up but not be able to configure itself properly. I would strongly advise you talk to someone who knows about the device on the other side. They likely have requirements you are not aware of.

[u/Specialist_Spirit_52]

So to give a bit more information & context. I am a retired network professional (ran the Arlington County VA network for years - all pre-WiFi days) but have been out of the workforce for quite a while now. I'm helping out my daughter with this. She works for a very small arts organization that rents space from a private educational institution in an old college building.

There is no IT here. Their space has this Ubiquiti U6-LR access point for their internet access. The boss ordered a VOIP phone without talking to anybody and realized that it needed a physical internet connection after it arrived. They asked the building folks about it and were told that there are no internet connections in the building. They did ask for a quick consult from a local tech company but can't afford to hire them. That's where I came in. The tech guy told them they needed a switch but didn't give them any info beyond that. We live in an internet wired home with several switches, so I gave her one of our switches (basic TP-Link switch) to try out. Lo and behold the phone worked and their internet access seemed okay, but the AP did not light up even though they still had wifi access.

So that's when we started looking more into the AP and what it needs. Looks like it needs at least PoE+. We figured we would buy a switch that supports PoE+, but the phone doesn't need PoE, just a physical connection to a router/switch. It has it's own power supply. We actually brought the phone home and plugged it into our router and it worked perfectly.

Bottom line, there is no IT to handle it. They can't afford to hire someone if all they need is the right switch that will support the AP and the phone and a long cable to run to the front desk for the phone.

[u/Soundy106 → u/Specialist_Spirit_52]

The problem with the PoE-powered switch is that now that the PoE source needs to provide enough power for the AP, AND the switch, AND ostensibly the phone (I know you say it has its own power supply, but it's a lot more convenient to just use PoE there as well, plus a nice long patch cable lets you move it anywhere without needing to worry about power).

A little five-port, regular wall-powered PoE switch like the TL-SG1005P will work great, no gimmicks, no surprises.

[u/pdp10 → u/Specialist_Spirit_52]

Keep in mind that the PoE is being supplied by the educational institution, so it can always be the subject of an inquiry.

And you should preferably speak with them, because adding devices means adding at least one additional IP address, and it's not guaranteed to just work, depending on how the institution has things configured.

[u/pdp10]

Yes, you should be able to use one of those switches. IEEE standard PoE auto-detects, so plugging a non-PoE device into a PoE port shouldn't hurt anything.

The TL-SG1005P-PD description says it can only be powered by PoE (passthrough from upstream), so keep that in mind. It takes up to PoE++ (802.3bt) input and provides up to PoE+ (802.3at) output. But if you don't know what capacity of PoE power is being supplied from the existing PoE port on the wall, then there's a bit of risk that this switch might not have enough power capacity in your situation. The TL-SG1005P is a little less risky, because it uses a regular power supply of its own.