What is Power over Ethernet ?
-As defined by the IEEE 802.3af committee and ratified in June of 2003, Power over Ethernet (PoE) provides 48v DC over the unused pairs of Category 5 or better UTP LAN Data Cables. Ethernet Data signals continue to travel on wires 1,2,3 and 6. Power is either superimposed on the data wires (Endspan technique) or routed to the unused wires (wires 4,5,7 and 8 this is the Midspan technique). The End device to be powered picks the power off of its RJ45 connector and routes it into its power circuit. This eliminates the need for the End device to be powered locally from a 110v AC outlet. Up to 15.4 watts is provided to the End device per the 802.3af PoE Standard currently in place.

Is PoE called by other names ?
-Yes. It is also referred to as Power Injection or Power over LAN.

What are the common uses for PoE ?
The First and still largest application is for powering Voice over IP Phone sets which unlike traditional phones are not line powered. Each phone set needs a power connection or it will not operate. The next largest use is for powering Wireless LAN Access Points (antennas) which typically install in locations without easy access to 110v outlets. Another fast growing application is for powering IP Based Security cameras which again often install in locations without a 110v outlet.

There are many emerging products which Manufacturers are making PoE ready as a competitive advantage vs. traditional powering techniques.

How do I know that PoE Technology is safe?
- The IEEE Standard addresses this question by instituting a feature called "Detect". The Power Supplying Equipment ( The PSE is the Powered Switch or Midspan Hub) first sends out a small test voltage called Detect and looks for an answer back from the PD (End device). If the PSE gets the correct response back (from a PD wanting PoE) only then does it forward power to that End device. The continual checking on the power requirement is called the "Detection Signature". If the Detection Signature becomes broken, meaning the End device has been removed from its LAN Data cable connection, The PSE immediately stops forwarding power out to that cable segment. There cannot ever be a case where power is "accidentally forwarded" out to a segment without a correct PD.

How much Money can I save using PoE vs. Standard 110v outlets?
-This will vary, but here is a rule of thumb. Midspan PoE products from LAN Power Systems are generally purchased and installed for $50 or less per Port (meaning per powered device). Ask your Electrical Contractor for a quote on installing a 110v outlet and depending on what City you are in, you could pay anywhere from $300.00 to $700.00.

So on average, it can cost $500 to power traditionally vs. $50 to power the new End device with PoE. Save up to 90% with Midspan PoE.

How do Manufacturers make their products work with PoE ?
-All Manufacturers have access to the IEEE 802.3af Standard, it is available publicly and free of charge. They design PoE , instead of traditional 110v AC power input, into their product designs. They then purchase PoE ICs from other Technology Companies and Integrate them into the End Device design. The PoE IC takes care of all the power supplying functionality for the End device.

How do I know if a Manufacturer's product will work with PoE ?
-Most manufacturers treat PoE compatibility as a feature. Look for it as a feature on the Data sheet of the product you are evaluating (IP Phone, Access point, IP Camera, etc.). If you don't see it listed as a feature, look at the product specs, under powering, if it says "PoE enabled" or "48v PoE" or "IEEE802.3af PoE" it will be PoE compatible with powering products that produce 802.3af style PoE output. Another way of checking is to look at the Compatible Products Listing found in the Support section of this website. This chart shows many of today's products which have been made PoE compatible.

Can I use PoE to power products that are not ready (made) for PoE ?
-Yes. Traditionally powered low voltage End devices taking 24v, 12v or 5v and wattages up to 15 Watts can be powered using the LAN Power Systems Voltage Adapter Product Family. See Products section of this website for further details.

What kind of cable system do I need to use for PoE ?
-Any 8 wire (4 pair) UTP LAN Data Cable that is rated Category 5 or higher ( Cat 5e or Cat6 for example). Basically, the cable you most likely have installed now or any new cable you are installing will work for PoE applications.

Are there distance rules for PoE, like with Ethernet ?
-Yes, the same distance rules for Ethernet apply for PoE. 100 Meters maximum Segment length with patch cords, etc. While we know of applications where PoE is successfully running at distances of up to 125 meters, we cannot guarantee this kind performance in your Network. You can always try longer distances and see if they will work.

What is Endspan PoE ?
-This technology refers to an Ethernet or Fast Ethernet Switch with optional built in PoE or "Powered Ports". Some or all of the Switch Ports may be powered. The powered Switch may or may not be able to develop full power on all Ports at the same time. For a more detailed look at the features of Endspan PoE, check the PoE Technology section of this website

What is Midspan PoE ?
-This technology refers to a Power Hub (or Power Injector) that is used in combination with a non-PoE Switch that the End user already has in place. Think of it as accessory or add-on PoE. The Midspan Power Hub costs substantially less than a new PoE enabled Switch as well as offering the End User numerous PoE Port count options. For a more detailed look at the features of Midspan PoE, check the PoE Technology section of this website.

Can I use both Endspan PoE and Midspan PoE on the same Network ?
-Yes, the Network does not care at all if Endspan is used for some links and Midspan used for other links. End devices are capable of deciding for themselves whether to take power off of wires 1,2,3 and 6 for Endspan PoE or 4,5,7 and 8 for Midspan PoE, no programming or set up is necessary for the End device.

What is "Power Management" and how come LAN Power PoE products don't use this?
-"Power Management" refers to the process of allocating a limited amount of total power available out to the total number of Ports (usually 24). In simple terms, most other brands and models of PoE products do not have enough total power available to be able to supply the 15.4 watt maximum to all 24 Ports at the same time. To make up for this deficiency, they must "Manage the available Power" to let Users know, through complex software programs and GUI interfaces, how much power is being used by each Port and how much is left for the remaining Ports. This is a total waste of time and resources for the End user. Worse yet, other Manufacturers treat "Power Management" as if it were a feature. At LAN Power, all of our products are built with more than enough total power to provide at least 18 watts to all unit Ports at all times. This exceeds the IEEE 802.3af standard. We don't have the "Power Deficiency" problems that other Manufacturers do, so we don't need to use "Power Management" software in any of our PoE products.

Will the IEEE 802.3af PoE Standard be changed or upgraded?
-Yes, but the current standard will remain in effect and be supported by a large number of Technology product Manufacturers. The working name for the Upgraded Standard is "PoE Plus". It mainly refers to the amount of wattage capable of being delivered to the End Device. The current PoE Standard is 15.4 watts maximum (This number is effectively 12.95 watts at the End device). PoE Plus seeks to raise this wattage level to perhaps somewhere in the range of 35 to 50 watts. Work on the additional Standard is ongoing, watch for news in the marketplace and updates here on this website.

Should the PoE Hub be backed up with a UPS?
-Yes, If you are concerned with any interruption in Service to End device functionality, then use an appropriate UPS to add Battery back-up in case of a loss of Building Power.

Can I run PoE outside for a Security Camera outside my Building?
-Yes, as long as the PoE Hub itself remains inside your building and you don't mind running your UTP cable outdoors, this will work.

How come you guys know so much about Power over Ethernet ?
-Its all we do. It's all we've been doing for years now. We're specialists in Midspan PoE Products and we intend to stay that way.

Please write to us in the Question Box on our Home page with any other PoE related questions you may have and we will do our best to answer them promptly.