Bus topology, which is sometimes also referred to as line topology, is a network setup where each device gets connected to a single cable. This connection is often called the “spine” or “backbone” of the setup for each workstation. Depending on the equipment being used during the installation, a network or coaxial cable usually helps the computers speak with each other by sending data packets throughout the system.
One way to think about this system is to envision the network like it is an aisle at your favorite store. The signal travels down the line to find the node that requests delivery. Then each end of the aisle as an end terminal that prevents the data packets from traveling to another network.
If you have a linear bus topology, then there is only one line associated with the design with two distinctive endpoints defining the system. When a distributed approach is preferred, then there can be more than one linear pattern as part of the network design.
When examining the advantages and disadvantages of bus topology, it is essential to balance the simplicity and cost of this system with the vulnerabilities of the design.
List of the Advantages of Bus Topology
1. A linear connection is very easy to install.
The reason why a bus topology is so popular is that the design is so easy to install in almost any situation. Because it uses a linear approach, you can always add new devices to the end of the network without disrupting the functionality of the other workstations. You also get to save on the amount of cable needed (if a wireless system isn’t being used), which can reduce the price tag on this work.
2. This design is the cheapest one to install today.
A bus topology is a cheaper design than any other network, including ring or hybrid options. The linear nature of this approach is what creates an advantage. All you need is a single cable strand with terminators on either end to build functional topologies. If your business requires a small network with high-reliability levels, then this is the approach to use.
3. The failure of a workstation may not impact the rest of the network.
Each unit transmits data packets to the spine of the bus topology installation, making it available to any other workstation who might need to access the information. A malfunctioning unit will disconnect itself from the Ethernet because its connection gets severed since the node is no longer available. These malfunctions don’t come with the risk of having the entire network go down as it can with other designs.
4. Connecting new devices to the network is a simple process.
If a new workstation comes equipped with the correct network card, then installing it on the topology is as simple as connecting the node to the spine of the system. As long as the unit isn’t outside of the terminator on either end, it can function with the rest of the nodes immediately. Although you don’t want to overload the backbone as this can slow down the functionality of the system, it won’t take away from productivity that is possible with this network design.
5. Bus topologies don’t require any switches or hubs.
The linear nature of the network allows data to flow freely throughout the system when choosing a bus topology design. Although this limits the number of possible outside connections to zero in some situations, it also creates a localized network that effectively works with each connected workstation. Then a central file server gets used instead of switches or hubs so that there are fewer potential failure points to manage with this setup compared to topologies.
6. It is possible to extend the length of the backbone of a bus topology.
There are natural limitations to the size and scope of a bus topology design. You can extend it by creating more length to the spine, removing the end terminals as needed to place more workstations on the network. There is also the option to join the backbone with a connector or repeater that permits more additions, and wireless designs provide almost unlimited potential in this area.
When you add more individual nodes to a bus topology, then the risk of data packet collisions will increase. If your primary goal is to get several workstations operational at once for the lowest price possible, then this is the solution to consider.
7. Bus topologies support the functionality of smaller systems.
Small networks often look at point-to-point network designs because the direct connection allows for immediate communication. Bus topologies follow the same principle with the exception that multiple nodes receive support. Most of today’s Ethernet systems got their start with this setup because of how simple and effective it is to encourage workstation communication within a confined environment.
This setup works well with peripherals that multiple workstations must share in a local environment. If you have three offices that need to share a computer, putting them onto a bus topology is an affordable way to maximize productivity levels.
8. The wiring terminators for a bus topology don’t have any power requirements.
Bus topologies use passive devices for their end terminators, which means the installed limits for communication won’t create a power drain that requires management. This technology uses capacitors and resistors to ensure that the data packets don’t go wandering off to another backbone. If you want to install a simple LAN, then you can do so at almost any location without needing to completely rewire everything.
9. Bus topologies can support multiple peripherals on the same network.
Printers, routers, and other devices that support receiving data packets can get connected to this network. Terminals, computers, and workstations are common nodes that you’ll find with this setup. If a wireless backbone is available, then tablet PCs and smartphones can also connect. When orders get sent over the spine, the local speed of information movement encourages higher levels of productivity. That means a well-designed system can support high levels of work.
List of the Disadvantages of Bus Topology
1. Determining the location of a fault can be challenging.
Bus topology makes it challenging to find a fault or malfunctioning workstation because of the linear nature of the design. It isn’t like the ring topologies that use a tokenized system that can show where a blockage occurs. All you know is that a disruption occurred. It’s a lot like a strand of Christmas tree lights that goes out. You can spot where an error happened because part of the string is no longer functioning, but then you’re forced to test each connection until you find where the problem exists.
2. Each new node will slow down information transfers with bus topologies.
Bus topologies link each workstation or peripheral through the backbone to encourage information transfers. That means additional devices will slow the entire network down since everything connects through a single cable. Some designs use two or more cables to reduce the risk of data collisions, but that option also negates some of the cost benefits that come with this approach.
That’s why a bus topology is typically regarded as an excellent solution for small networks only.
3. A failure of the backbone can be catastrophic.
If something happens to the spine of the bus topology, then the entire network can go down immediately. You would still have node connections on either side of the break, but there wouldn’t be effective communication throughout the entire system. If a workstation is on one side of the fault and a printer is on the other, the two would be unable to communicate with each other until a repair gets completed.
4. There are always size limitations in place with a bus topology.
The backbone of a bus topology can theoretically have an unlimited length, but larger sizes will slow down the speed of data packet transmission. You must limit the size of the backbone to ensure efficient communication practices. That means a maximum number of nodes can be on the system before it becomes an ineffective way to transmit information. Each terminal that goes onto the spine will create a higher risk of having a data collision occur within the system since the spacing is at such a premium.
5. Bus topologies struggle to offer sufficient security protections.
When you have multiple nodes attached to a backbone, then each workstation has the option to view each data transmission as it occurs from every other connected terminal. The efficiencies that bus topologies provide rely on having each device having complete access to every other station on the system. That means administrators must create security protocols that protect the entire installation instead of only focusing on each terminal.
If an unauthorized party were to gain access to one terminal, then that workstation would immediately compromise the entire system.
6. The maintenance costs of bus topologies are typically higher.
It is cheaper to install a bus topology compared to the other designs that are available today. It is also more expensive to take care of this system despite the fact that you’re only maintaining a single backbone in most situations. This design isn’t as scalable, which means the cost profile increases in the long-term perspective.
If you know that a small network is what you’re always going to need, then this system makes sense to use. When your goal is to grow as a business, then a different topology should be looked at first to see if the long-term cost profile is better.
7. Data quality issues can develop in bus topologies.
When a large bus topology is under a high level of stress, then the levels of data loss can be massive. If data packets collide with each other, then the information loss can impact your overall productivity in multiple ways. Some nodes may never receive the commands that get initiated at a terminal, which means repetitive work must take place. If you’ve sent a print command from your computer that never initiated the peripheral, then you experienced this disadvantage of bus topologies.
8. The termination points on the backbone can interfere with the network.
When improperly designed termination points are on either end or both ends of the backbone, then communication problems can develop rapidly with bus topologies. The terminators must be at the two extreme ends of the network instead of separating the backbone into individual components. That means the placement tends to be at the controller and the furthest point away from it.
There can be lengthy identification process issues with the network because of this design requirement. Some baud rates can successfully communicate to ports outside of the termination points if shared wiring occurs, leading to data leakage issues that can be quite problematic.
9. Sharing data isn’t the same as communication.
Bus topologies would have a higher efficiency rate if the workstations could coordinate with each other regarding data packet transmissions. Since each node can initiate the release of information independently of every other one, that means the backbone may need to support multiple transmissions simultaneously. This outcome creates a heavy traffic level that increases the risk of a loss occurring.
Some designs use repeaters as a way to strengthen the resiliency of the data packets being sent across the bus topology. Even with this safeguard in place, this disadvantage can become a problem for larger systems.
10. The T-connection in a bus topology is a weak point of the design.
Each workstation, peripheral, and node connects to the backbone through the use of a T-connection point. This design is what creates the independence of the network. Bus topologies don’t provide any redundancies to this point, which means a failure there will immediately disconnect the terminal from the rest of the network.
Because workstations have offline capabilities that don’t always require network access, it can be some time before the disconnection gets noticed.
Bus topologies are highly valued because of their lower cost of implementation and their overall simplicity. The drawback of this design is that a compromise of the central line will cause the entire network to experience a failure. Problems with data loss can occur with longer backbones, and it can also be difficult to troubleshoot issues with this type of design.
When any segment or link of the bus topology gets severed, then all network transmission could fail because of signal reflection. The cause of this issue is the lack of electrical termination.
That’s why these bus topology advantages and disadvantages must receive careful consideration when designing a new installation. The lower cost of this system with its easy connections can seem like a benefit, but this option typically works best when you have a small network to manage.
Brandon Miller has a B.A. from the University of Texas at Austin. He is a seasoned writer who has written over one hundred articles, which have been read by over 500,000 people. If you have any comments or concerns about this blog post, then please contact the Green Garage team here.