Sorry to refresh this thread. I’ve bought a cAP lite thinking to use a Netgear GS108T-200GES or a Tenda TEF1105P-4-63W. This because I need to set up a wireless system at school with a very low budget. Unfortunately neither the first nor the second switch is powering the cAP using a direct or a crossover cable. Based on the wiki I was assuming that at least using a crossover cable the cAP was adherent to 802.3af, but nowadays seems not. Does Mikrotik has any cost effective (I mean that costs less then Ubiquiti) AP with full 803.2af support?
The CAP lite does not power up using a Tenda TEF1109P or TEF1105P, even though both switches supposedly complies with the 802.3at/af standard.
Can anyone explain why the CAP lite won’t work with all switches that uses 802.3at/af?
Indeed support for 802.3af/at seems like a small magic in Routerboard devices. Even official compatibility matrix shows need for crossed cables with some RB devices, including cAP lite.
The table actually suggests (based on columns 2 and 3) that some RB devices are picky about polarity (and not all of them prefer same polarity) while some devices aren’t.
PoE article on wikipedia offers some explanation about need for cross-over cables (in the Powering devices section). Seems like PD (power sink) is responsible to implement kind of a “auto MDI/MDI-X” operation for PoE, PSE (power source) will always output same polarity.
My guess is the PD has the resistance installed on another pair from where the PSE sends the signal, thus not detecting PoE on the device and not powering it up. By doing a crossover cable, the signal gets response and powers it up.