Nowadays our life are connected to the world with or without our knowledge. In such world, we cannot afford to neglect the importance of logical security. The seven layers of network shall be carefully planned and properly secured.
Here are the seven layers of network put into context for easy understanding:
1) Physical: such as the metal copper or optical fibre
2) Datalink: your network switch works in this layer. MAC (media access control) address works in this layer and allows two or more devices to talk to each other effectively.
3) Network: Routers and Internet Protocol (IP) address are in this layer.
4) Transport: TCP works here.
5) Session: establishing working communications between applications.
6) Presentation: translate information into format that applications can use.
7) Application: the browser that you are using now.
This security frontier is invisible but could become the weakest link of your security system.