What is a Network Diagram?

A computer network is a collection of computers devices connected by communication devices for the purposes of sharing resources. A network diagram is the graphical depiction of the computer network. Typically a network diagram will include a visual schematic identifying computer devices and communication devices within the entire network.

Today there are multiple types of computer networks. These include local area networks (LAN) and wide area networks (WAN). Network diagrams are a used as a tool to describe the physical layout of a computer network. This diagram typically includes the protocols, network addresses, and open ports used by computer devices. The scope of the network diagram can range from a simple single network to complex enterprise network design.

A network protocol is the communication standard that defines how information will be transmitted over a network to a computer device. Today there are many protocols available within networks. It is important to define these protocols on the network diagram to ensure proper security and architecture is appropriately applied.

A network port is the end point or channel that is used for transferring data between computer devices. Typically each protocol has a standard default port defined. As an example, most Internet websites use the hypertext transfer protocol (HTTP) protocol. This protocol uses port 80 by default.

Complex computer networks require switches, routers, hubs, and load balancers to ensure efficient communication across the entire network infrastructure. These network devices are typically included within a network diagram. Each communication device has the potential for failure. The network diagram can be used to pinpoint system failures when they occur.
Network monitoring tools are used within most enterprise production networks. These monitoring tools track devices by an Internet protocol (IP) address. When a network device has a failure, error messages are reported to a network administrator. The administrator will use the network diagram to determine the port and IP address of the problem device.
The network administrator has the responsibility of managing and routing network traffic among devices on a computer network. He can be considered the traffic police of the communication highway. The network diagram is an invaluable diagnostic tool for the network administrator in performing his job.
Today there are automation tools that can be used to create network diagrams. These tools range from simple graphical creation programs to complex schematic- generation tools. This software simplifies the management and creation of complex network diagrams. Typically these software packages will include predefined templates based on the network type.