Bus topology isn’t a reference to vehicles. It is a network setup that involves computers and network devices. Each is connected to a single cable, which is called a “backbone” or “spine.” This creates a localized network that can be used for a variety of purposes.
The primary advantage of bus topology is that it makes linear connections much easier to complete. Peripherals and computers can be added to the topology of the network in a linear fashion without the same demands for cable length that a star topology link would require.
As for disadvantages, bus topology makes it difficult to determine a network problem if the entire system goes down. Individual device issues can also be difficult to troubleshoot, which means it is not a great setup for larger networks.
Here are additional advantages and disadvantages of bus topology to think about.
What Are the Advantages of Bus Topology?
1. It is easy to connect a device to the network.
If the computer or peripheral has the appropriate connection mechanism, then it can be easily added to the network. The new device connects to the linear bus topology and becomes part of the network immediately. For those who need a temporary network that can be setup quickly, there isn’t a better option that is available right now. If several users need mutual access to a printer, adding the printer to the network meets that need immediately.
2. It is cheaper than other network options.
Compared to ring, star, or hybrid networks, bus topology is the cheapest to implement. That is because it requires less cable length than the other network options. Although terminators are required at both ends of the backbone to ensure the network can function properly, it is still easy and affordable to install when a small network is required.
3. The failure of one station does not affect the rest of the network.
If one computer or peripheral should fail when using bus topology, the rest of the network is not affected by this change in performance. The linear nature of the network means that each unit transmits to the backbone and that data is then available to the other units that remain connected. This makes it an effective way to share uninterrupted communication.
4. No hubs or switches are required.
With bus topology, the linear nature of the network allows data to flow freely throughout the network. Although this limits outside connections, it does create a localized network that can effectively work with each terminal that has been connected. A central file server is used instead of hubs and switches, which means there are fewer points of potential failure that must be managed with this setup compared to others.
5. Extensions can be made to the network.
The size and scope of bus topology is naturally limited. It can, however, be extended quite easily. Joining cable with a repeater or connector allows for additional peripherals or computers to be added to the network. Although this can increase the number of packet collisions that may occur, it is a simplified solution that can get people up and working quickly and for a minimal overall cost.
6. Multiple nodes can be installed without difficulty.
For a small network, another option that is often considered is point-to-point topology. Bus topology has an advantage here because it supports multiple nodes instead of just 2 nodes. That is how the original form of an Ethernet network came about. 10Base2, which is popularly known as “thinnet,” utilizes bus topology to create a local area network that can be used to form departments or working groups.
7. Multiple peripherals can be supported through bus topology.
Routers, printers, and other data devices can be connected to this network in addition to computers or terminals. This can increase the speed of productivity because instead of sending commands to a centralized network, a command can be sent directly to the needed peripheral. A print command from a computer, for example, can stay local and improve production speed, which keeps workers more productive over time.
8. Wiring terminators take no power requirements.
The terminators that are used for most bus topology systems are passive devices. They’re made of resistors and capacitors, which means there isn’t a power requirement that must be met. This makes it easy to install a simple LAN at virtually any location where networking would be beneficial to a department or working group.
What Are the Disadvantages of Bus Topology?
1. Additional devices slow the network down.
Because bus topology links every computer and peripheral through a backbone, additional devices will slow down the entire network since only one cable is being used. That also places the entire network at-risk should something happen to that cable. If the backbone is damaged for some reason, it can either cause the entire network to fail or have it split into two networks instead of one.
2. Size limitations are always present.
A backbone has limited length, which means there is a maximum number of computers and peripherals that can be added to the network. That size limitation also increases the risk that collisions will occur within the bus topology because communication spacing is at such a premium.
3. Security options are limited with bus topology.
Any computer that is connected to the backbone of a bus topology network will be able to see all the data transmissions that occur on all the other computers. Each terminal has full access to every other terminal. That means security options are difficult to install on such a setup because everyone can see what everyone else is doing.
4. Maintenance costs are higher.
Although bus topology is cheaper to setup, the costs of maintaining this network are higher in the long run. It may be a good network for those with small, short-term needs. Because it is not scalable and the costs increase over time, however, it may not be the best choice for those who anticipate growth occurring within their network.
5. A break in the backbone can cause an entire network to collapse.
Because the size of bus topology is limited, a break in the backbone causes the entire network to collapse in some way. Full communication cannot be restored until the issue is repaired or the backbone is completely replaced. That means it cannot be used as a stand-alone solution. A breakage event will cause any computer or peripheral to lose its communication with devices on the other side of the network. Without a second terminator in place, the likely result is network collapse.
6. The quality of the data is placed at-risk on large bus topology setups.
In addition to the speed issues that occur with a larger network using bus topology, there are data quality issues that must be considered. When data packets collide with one another, the outcome is data loss. Increasing the number of nodes that are present on the network has a direct impact on the quality of communication that occurs. That is why the size of these networks is naturally limited.
7. Bus termination issues can lead to network issues.
Communication problems in bus topology can occur when there is improper termination. Terminators are required by ISO 11898 to be at the two extreme ends of the network, which tends to be the controller node and the node which is furthest away from the controller. Even if termination is not appropriately used, certain baud rates can still be successful in their port-to-port communication, which can lead to a lengthy identification process of the network issue.
8. The computers may share data, but they don’t communicate.
Bus topology would be much more efficient if the computers on the network could coordinate with one another regarding transmission times. They do not coordinate, however, which means multiple transmissions can occur simultaneously and this creates heavy network traffic with a high potential of data loss. Even if the backbone is extended with repeaters to boost the signal, there is too much simplicity in this network setup to make it an effective system for a large setup.
9. A T-connection failure immediately limits access.
Because each node is independently connected to the backbone, bus topology doesn’t provide a secondary connection resource. If there is a T-connection failure for the connection, then there is no way for data to be shared along the network or to the computer or peripheral that has been separated from the backbone.
It is clear to see that small networks that require a temporary solution benefit from the advantages and disadvantages of bus topography. In theory, there is no limit to the number of nodes that can be added to the backbone of this system, though additional units come with the risks of slow data speeds and quality issues can be encountered. Satellite offices and other small network areas can benefit from a permanent installation of this type as well.