Communication over a shared Medium

	Participants have to have a way not to talk at the same time.
	Participants have to talk the same language / protocol.
	The used protocol has to be an Internet standard
	One has to ensure that everyone gets the same amount of time to put data to the shared medium.
	Communication must be encrypted.
	One has to make sure who sends a message and to whom it should be delivered.
	Messages have to be delivered correctly and be secured against data loss

	The smallest amount of information that can be transferred is a Bit.
	Everyone who has access to the medium can receive all the data that is being put on the medium.
	Several computers use the same medium to communicate with each other
	Collisions will occur if using a shared medium .
	Communication must be encrypted.

Web Science/Part1: Foundations of the web/Ethernet/Communication over a shared Medium