If you have lots of Ethernet switches that you want to convert to PoE switches, the place to turn may be a midspan.
Power over Ethernet (PoE) is a standard for transmitting both electrical power and an Ethernet signal over the same line. Common applications would be IP phones and network-connected surveillance videocameras, which could be located in places where it’s much easier to run one line rather than two.
This can be achieved by a PoE-enabled switch, but there is another way. A midspan is a device that takes in an Ethernet signal from the cable on one end, adds electrical power, and then sends both signal and power down the cable on the other end. Instead of ripping out Ethernet switches and replacing them with Ethernet switches that support PoE, you simply add midspans where you need them.
Another device that could be helpful is a splitter. If you have older end devices that don’t accept power through their Ethernet cables, you can stick a splitter onto the end of the Ethernet cable, and it will split the signal onto one line and the power onto another.
PhihongUSA promotes the use of midspans via its site midspans.com. There you’ll find the case for using midspans – the fact that you want your data switches to focus on what they do best, for example.
PoE was set forth in the IEEE 802.3af standard, and a follow-on standard, 802.3at, is close to ratification. The original standard allowed for 15.4 Watts, while the newer version is intended to provide 24 Watts.
And then you have Phihong, which on its site lists possible applications of PoE at 60 Watts, 80 Watts – even 120 Watts. At those levels, you could power LCD displays or workstations. And yes, you would likely use a midspan to deliver that kind of power, rather than try to rely on an Ethernet switch to do it.
