Overview
IEEE 802.3af came into a world in which many devices were already out in the field working off power delivered via an Ethernet cable. Businesses had not been sitting around waiting for an open-standard to emerge and be gradually ratified. The idea of sending power over the same cables as data/voice was as appealing now as it had been over a hundred years ago. Why wait?
Initially, IP phones were meant to be supported, but later powered wireless-access points (based on 802.11) joined in too. And that was the only thing that was clear! A big problem was that all these “legacy” or “pre-standard” PDs, as they are called today, were based on proprietary implementations of PoE, such as Power over LAN (or PoL, from PowerDsine, now part of ...
Get Power Over Ethernet Interoperability Guide now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.