Hi. My understanding is that a port is basically a number assigned within an IP packet which would allow the packet to be directed to an associated program in the PC (or whatever computer). It would seem to be just a sort of coding scheme or addressing scheme. Recently I have heard, within discussions of net neutrality and regulation of the net, that some telecoms have attempted to block ports. In the particular discussion I heard, it said that a telecom company had attempted to block voip ports for Vonage or Skype. Given that a port is just a number, I don't understand how the blocking of a port could take place. I would love to hear how this is done or what it means.