Network Topology: Types and Uses

Network topology is the configuration of nodes and connections between network hardware that form any given computer network's physical and logical structure. It is essentially a map of how data moves through your system. Network topology dictates the flow of data packets so businesses can have an efficient network to save time and reduce costs. A well-structured network is easier to troubleshoot and fix when problems do arise.

Read on to take a closer look at network topology uses, the types of network topology available to network administrators, and how to start a career in networking. 

What is network topology used for?

Network topology is a way of creating networks with speed and efficiency. Network administrators must understand how their specific network functions so that they can troubleshoot any issues that arise. Network topology gives administrators a visualization of the network's construction and how each device connected to the network behaves. It puts IT in the best position to maximize efficiency, diagnose and troubleshoot problems, and allocate network resources in an organization. 

How does network topology work?

Network topology works through two kinds of topology that arrange networks: physical and logical. Let's explore both types:

• Physical: Also called the underlay, the physical components of a network include cables, routers, and hardware. Underlays are a network’s material wired layout and map physical connections. These tend to be more difficult than logical networks to reconfigure as your organization evolves simply because they are hard-wired, not programs.

• Logical: Also called overlay, the logical topology directs data movement through a network. Logic, not physical connections, directs the flow of data from one device to another, and the overlay maps the path along which data travels within a network. Logical networks use data packet headers to manipulate how data flows through the networking, making them flexible and scalable in ways the physical topology can’t be. 

Understanding these network topology components is important during network design so administrators can avoid slowdowns and bottlenecking. The physical topology must be as malleable and scalable as possible to optimize overall network functionality for an evolving organization. Let’s take a closer look at some network topology types. 

Network topology types

Network administrators use network topology to determine how to organize their systems' various nodes and links, but they don’t have to reinvent the wheel every time. Several types of network topologies act as templates. These include:

• Ring topology

• Star topology

• Bus topology

• Tree topology

• Mesh topology

• Hybrid topology

Let’s closely examine each network topology type and best use cases. 

Ring topology

Ring topology arranges devices in a circular formation, and all data travels the same way around the circle. Data packets move from one device to another until they reach the intended destination. Since all data flows in one direction, ring topology creates high efficiency without a central hub. 

The ring's simplicity also makes it easy to troubleshoot. However, if one device in the ring fails, the entire network is typically impacted. To prepare for this, some ring structures use two rings, one sending data clockwise and the other counterclockwise. 

Star topology

In star topology, devices connect to one central point, typically a router or switch, through a physical connection like Ethernet cables. When a request occurs, the data packet is first received by the center point in the network, which transmits it to the intended device. 

This topology does not depend on each node within the network for its function, just the central node, reducing network failure. It also allows for connection or disconnecting different devices but suffers slow speeds when overloaded with requests. For this reason, star topology works best for small networks.

Bus topology

In bus topology, all devices connect to one shared connection line. It is the simplest way to set up a network, but it can cause issues when multiple devices make requests simultaneously, leading to slowdowns. If an individual node fails, the rest of the network experiences no further harm. However, if the bus line fails, the entire network goes down. 

Bus topology uses end terminals to stop the signal line from continually flowing back and forth. Linear bus systems are challenging to troubleshoot and often have signal loss due to using the singular connection. 

Tree topology

Tree topology organizes star topology hierarchies using central nodes like routers and switches. This organization makes tree topology scalable and easier to troubleshoot. 

Multiple star topologies form a tree topology when they connect to a singular network node. This topology splits networks into various branches of star networks that all connect back to one primary node, which gives it its tree-like appearance. Its main disadvantage is its dependence on the singular, primary node. If that node goes down, the whole network does. 

Mesh topology

Mesh network topology interconnects all devices on the network into one mesh. Each device transmits its own data and acts as a node for other data packets to travel to and from. It gives networks redundancy in their creation. If one node fails, the data can still follow many different paths. However, this requires lots of hardware and cabling, making these kinds of topologies expensive to implement. Wireless networks are a less costly option for a mesh configuration. Wireless mesh networks work with an access point instead of a cable between each node. 

Hybrid topology

Some organizations opt for hybrid topology, which combines multiple topologies connected to one central node. This topology can link old systems with new systems within a single network. It is expensive to set up and maintain due to its unique implementation, but it does not depend on a singular topology for the entire network.

Who uses network topology?

Every network, from small businesses to enterprise networks, relies on network topology. It is essential to any organization because your network configuration affects your system's latency, scalability, security, and maintenance costs. Network administrators and network architects work especially closely with topologies. Network administrators use network topology to troubleshoot issues that arise and maintain efficient operations, and network architects use network topology when they design new network configurations according to their organization’s specific needs. 

Which network topology is suitable for you?

Choosing the right network topology for your business comes down to various factors. Four essential considerations include:

• Physical size of the network: The physical size of your network and the amount of cable you need will affect your costs, flexibility, and installation. Bus and ring networks require much less cabling than tree or star networks. 

• Type of cable used: The speed you need will dictate the kind of cable you use. For instance, you may choose fiber optic cable for higher bandwidth and transmission over longer distances, although it can be more costly than coaxial cables. 

• Budget and cost: The length and type of cable will dictate the budget and cost of implementing your network. More extensive, more complex networks require more time and material to install than smaller networks. 

• Scalability needed: Certain networks are more scalable than others. If your business grows, a scalable network like a star topology gives more room for future growth than a ring network.

How to get started in network topology

Network topology is one of the most essential factors in determining how network devices communicate with each other and the speed and efficiency with which data moves through the network. Much network topology planning falls on a network architect, a high-level networking job requiring at least a bachelor’s degree in computer science, engineering, or a related field. That said, many network architects need a master’s degree and at least five to ten years of experience in the field. 

Understanding network topology is vital for entry-level positions like administrators, technicians, engineers, and IT professionals who maintain, implement, and troubleshoot organizational networks. 

Next steps

Network topology consists of the physical and logical layers of a network or the arrangement of the physical hardware and how the data flows through the topology. You can choose from many different types of topology, including ring, star, bus, tree, mesh, or hybrid topology configurations. To determine which is right for you, consider your needs for network size, cabling, scalability, and your time and budget constraints. 

Ready to upskill in your current job or learn more about networking fundamentals? To enhance or start a career in networking, explore courses available on Coursera like the Google IT Support Professional Certificate, Information Technology (IT) and Cloud Fundamentals Specialization from IBM, or Princeton University’s Computer Architecture course.