This is a network diagram for CCTV. Simply put, a network diagram is a schematic or map of your existing network that depicts the nodes and their connections. Network diagrams are extremely useful for mapping out your elements and device interactions, as well as illustrating various network topologies. Network diagrams come in a variety of shapes and sizes, but they can be divided into two types: physical network diagrams and logical network diagrams. Now it is easy to create a network diagram with EdrawMax.