My company just bought some spa504g. The technician that sold them us, assured that they would work being powered from our Catalyst 3500 XL.
Since apparently the spa504g does not work with our switch's POE, we would like to know whether we need some additional system/machine to make them work.
Our main trouble regards the power supply form the switch. The voip network as well as the telephones (spa504g) do work fine.