Oddly enough, and despite the fable you posted from the article, IP Phones are not friendly to a fiber-to-the-desk architecture. The reason is this: IP Phones require power from either a power adapter and a separate ac outlet, or from the Ethernet switch over the same copper wires that feed the Ethernet frames to the desk. Here, the power is delivered over unshielded twisted pair, typically Cat5 or Cat5e, piggybacked on top of the data.
The latter (using Catx UTP) is, on the surface, far less expensive than the combined use of fiber _AND_ tying up a separate power outlet and a.c. circuit from the power distribution unit to the desk, and then supplying the adapter, to boot.
Standard dumb phones, on the other hand, have always taken their power from the PBX over the same wires that are used for the voice path.
Future VoIP at the desk level, when they begin hanging off of PCs, will not have this problem (in the latter case you must have your PC turned on in order to use your IP Phone!), although standalone IP Phones will still require a separate power source. Funny, isn't it? You progress to IP telephony at the desk, and you can't use fiber. Unless you pull another electrical circuit to support an a.c. to d.c. adapter... which, combined with the separate power circuit, is more expensive than either UTP _OR_ Fiber.
One solution to this deadlock (there are distance formulas to consider, so it's not as straightforward as one would ordinarily think in determining cost-benefits) is to run both fiber (for data and VoIP apps) _and_ a separate low-quality (non-data-rated), low-voltage-rated twisted pair for the delivery of -24v to the IP Phone.
BTW, the IP phone in the workplace thing is chuck full of surprises. Yes, it starts you in the right direction (assuming it's "right") towards a "converged" voice and data environment. But implementing it is data-skills intense at the call server and gateway levels, and voice-skills intense at the telephony and carrier-relations levels. This is one reason we are seeing an increasing number of political science grads with advanced degrees entering IT these days. |
