I have a question about wifi networks and total available bandwidth. According ot the specification, the wifi has a certain transfer rate. So, if I have an AP that supports 300mbps, and X connected clients, the total bandwidth is splitted among the clients or the transfer cap is per client?

among the clients but I assume that your router is connected to ethernet cable, which's bandwidth is limited to 100mbps so, well

wifi is still a shared type of architecture...however some of these routers are dual/multi banded so you can seperate traffic... either way, basically in a shared type of network the bandwidth is not per client, but shared among them.

I'd use the example of ethernet.. you have ethernet and fast ethernet. ethernet is a shared. When you connect a bunch of hosts to a hub, the available bandwidth is shared. when you connect to fast ethernet and your hosts are connected to a switch, bandwidth is not shared between the switch port and endpoint/host.