Computer Network Diagrams

When you walk into most modern work offices, there is a good chance you will be greeted by banks of computer screens and terminals, perhaps some sales points screens or server stacks, almost certainly routers and printers. A side effect of this amount of hardware is the amount of cabling necessary to connect these elements into an effective local area network (LAN). With technology and market forces demanding ever quicker business response times, a well-structured computer network is the foundation of positive communication between employees, and with the wider world.

As anyone who has struggled sorting out all the wires behind a television can empathize, it's good to know which cables go where, and what is their function. This is the idea behind a computer network diagram — it can show how a network is connected, how data transfers between those connections, and give an overview of devices and hardware used. To create a practical diagram, the user must adhere to the specified requirements and limitations of the office or building in which the LAN will operate — things such as hardware availability, company budget and customer needs must all be taken into account.

There are two main forms of computer network diagram:

Physical topology diagram

These diagrams show the physical arrangement of a network, the order in which devices are connected, and the cables used to connect them. Which cabling to use is determined by the type of topology employed, and there are three main forms in use currently:

• Star — by far the most common topology, most people at home on their personal computer will be using a very basic form of this. At the center of the network is a hub, generally a router, where each device connects to it only. Data transmissions between devices is managed through this central hub, and sent from it over wired or Wi-Fi connections.
  
  
  

  Fig. 1. Star topology

• Ring — as the name suggests, devices using this topology have two connections, joining with neighbouring devices to form a loop. Data passes through the loop, copying itself to any destination address.
• Bus — similar to a ring, but the data travels up and down a linear cable, copying itself where devices act as 'stations' along the route. This method is useful for small networks, or when adding an extra device to one, but should the main cable fail it can bring down the network.

Logical topology diagram

A logical topology adds a further level of detail to a computer network diagram, by showing along which path data is transferred around the network, the network protocols that govern it, and how it is received by the various nodes and devices. They can show elements such as firewalls or software specifications.

While the logical topology can mirror the form of the physical, it is possible for them to be different. For instance, data travelling through a physical 'star' topology will travel ostensibly around a 'ring' within the router, checking whether each device matches the destination address.

Fig. 2. Logical bus with physical star topology

Network architecture

Combining the elements from these topologies creates a layered picture of the network architecture, which can basically be defined as the design of a communications network — a framework for its physical components, and a clearly defined set of principles and procedures. Although these rules can often be quite rigid, a computer network diagram does not just to be a simple arrangement of lines and text — computer network diagram symbols can added and utilized to represent real-world locations, end-user interactions, or specific hardware.

Logical and physical topology diagrams are ideal for depicting LANs, but often business demands a network on a much larger scale. A global network connecting devices in disparate areas is known as a wide area network (WAN), and it will generally use a dedicated form of connection in order to keep up communication, for instance satellite or leased lines. They can be shown on diagrams using the methods outlined above — the diagram will show a 'step back' from a LAN, showing the structure of connections between LANs within the WAN.

Fig. 3. Computer Network Diagram

Drawing tools from ConceptDraw

For many years, the software engineers at ConceptDraw have dedicated themselves to releasing innovative and comprehensive diagramming solutions, adding extra functionality to their award winning software, ConceptDraw PRO. Each one contains libraries of graphic illustrations and symbols, together with user-friendly templates to help the user get started. With the Computer Network Diagrams solution, network architects and heads of IT departments have an all-in-one drawing tool that provides indispensable vector stencils depicting branded hardware, telecommunication devices, and logical symbols that allow freedom of expression in diagram, however complex the network might be.

The support from ConceptDraw doesn't end with the solution libraries. Apart from the quick-start templates provided, the dedicated solution page contains a set of network diagram samples, showcasing the options and styles available. There is also detailed 'How-to' section that goes step-by-step through the process of creating a variety of diagrams, and of course a wealth of video and text material can be found through the ConceptDraw 'Help' section.

Whether rapidly sketching out a personal network, or visualizing complex topology to share with a company team, the Computer Network Diagrams solution for ConceptDraw PRO has all the tools needed to make productive and professional network diagrams.