计算机网络拓扑
Types of Computer Network Topologies
Nowadays, many people live in the modern world, and they need to use computer technology to make their work easy. When considering a computer network, it is a collection of computers which design to send or receive data. The term network topology is an arrangement of nodes such as routers, switches and connections. Accordingly, we can identify computer network topologies, connecting the sender and receiver through several connections. There are some different types of computer network topologies. We will be discussing the eight main types of computer network topologies in this article for your knowledge.
Point to point topology
Point to point topology is the most simplest topology to use than other computer network topologies. This type of topology is a one to one type of connection. It connects two devices or points in a network in this topology. Therefore using this type of topology, computers or devices can be easily connected using normal twisted pair cables. More than that, point to point topologies can also connect routers in a far distance. Computers connect directly with each other in this method. Point to point topology is also very reliable and faster than any other computer topologies. Some examples for point to point topology include connecting remote and television and children’s tin-can telephone.
Data transmission process happens in three ways in this point to point network topology. These three data transmission processes include simplex, half-duplex and full-duplex ways. In the simplex mode, signals always flow through towards only one direction. In the half-duplex method, both the sender and receiver can send and receive signals to each other, but they cannot communicate simultaneously. The full-duplex method provides the opportunity to send and receive the signals simultaneously. Even though this topology is very useful, there are also some disadvantages of using this point to point topology. Information cannot pass through this topology if one of the nodes break. Because of that, users have to replace a new device or a computer for this broken computer.
Bus Topology
Bus topology is a network topology which connects multiple computers through a single cable. Nodes are the common name given for these computers connected in a network. All these nodes link to one cable called backbone in this bus topology. As computers connect in the network, files and data can easily share within this network. Data always transmit in one direction in this bus topology.
When this bus topology has two ending points, it is known as linear topology. It is known as a distributed bus topology if it has more than two ending points. In a linear bus topology, all the data transmitted between the nodes in this network. Therefore all the nodes/computers in this network can receive the data transmitted through this common transmission medium. Ethernet cable, landline telephones are the most common examples of bus topology.
Bus topology is very useful as it is a simple design and needs fewer cables. But there are also some drawbacks to this bus topology. As this whole network has a single cable, the whole network fails to work properly if this cable gets damaged. Unlike in other topologies, as bus topology uses a shared connection between nodes, this topology is slower than the other topologies.
Star Topology
All nodes connect to a one hub using a star topology cable. This hub is generally known as the central node. All the computers have their connection to the central node in the star topology network. Therefore, the central node acts as the server and the other connected devices act as clients in this star topology. These networks are commonly useful in home settings. For example, to access the internet, we connect our laptops, smartphones to a wireless modem. This network is an example of a star topology network that we use every day in our home environment.
Star topology is a good network to use. If you need to add a new computer to your network, you can easily do it within star topology. Rather than that, if one computer within this network breaks, it does not influence other computers. Therefore, you can continue your work without any disturbance. But the cost is high, and it is a bit expensive to use. There is another main disadvantage of the star topology network. Even though if one computer breaks, others function normally, if the main hub breaks, the whole network system also fails to function. Because all these nodes completely depend on the central node.
Ring Topology
Ring topology is a simple design which connects all the computers to form a ring. Every computer gets two neighbour computers to get connected to this network. When sending data, it sends data in one direction. One of this ring topology’s special features is that every device in this network has a repeater. For example, think if someone needs to send data to the last node of a ring topology with 50 nodes. The data has to pass through 49 nodes to reach the 50th node. In these situations, repeaters are useful in a ring topology to prevent data loss. SONET ring networking is an example of a ring topology network.
Ring topology is easy to use as the installation process is much easier than other topologies. More than that, this network is the best way to provide good communication over a long distance. But there are also some disadvantages of ring topology. It will not provide the user with a fast service as the data always travel via every computer interconnected in this network. Like we mentioned in a star topology, if one computer breaks in a ring topology, it will also affect the whole system.
Mesh Topology
Mesh topology is different when comparing with other network systems. In a mesh topology, all the devices connect to each device on the network system. Two main types of mesh topology systems are there in this topology. Partial mesh topology systems and full mesh topology systems are those two types. Some devices connect to two or three devices in a partial mesh topology. But in the full-mesh topology system, every device in this network is interconnected with each other. Intelligent Transportation System (ITS) and Scottsdale are examples of business mesh topology networks in the US.
Mesh topology network provides high security and privacy for the users. It is also a strong network system which can detect faults very easily. But considering other topologies, it takes a high cabling cost. More than that, the installation process is also a bit difficult in a mesh topology network.
Tree Topology
Tree topology is easy to learn as all the computers are connected to form like branches of a tree. Hierarchical topology is another name as it consists of different levels to the hierarchy. This topology is mostly useful in wide area networks. It is a combination of both bus topology and star topology. B-trees are one of the similar examples for the tree topology network.
It is possible to manage and maintain tree topology network systems for the users pretty easily. But it is also highly cost and difficult to maintain if the user wishes to add more nodes to the tree topology network.
Daisy Chain Topologies
Daisy chain topology is a network system which connects multiple devices in a sequence. This network node is attached to the next line in a chain. Linear daisy chain and ring daisy chains are the two types of daisy chain network topologies. MIDI devices and Serial Peripheral Interface Bus (SPI) are examples of daisy chain networks.
Unlikely in other topologies, the data transmission process is super-fast in a daisy chain topology. It is much easier to manage this network topology as it does not require extra cables. However, there is a disadvantage that we should consider here. If the number of nodes in the network increases, it might cause to slow down the whole system in the daisy chain topology network.
Hybrid Topology
A hybrid topology is the network system which combines different network topologies such as tree topology, mesh topology, bus topology etc. Hybrid topology usage always depends on its requirements and topology’s performance. As an example of this hybrid topology, we can present a combination of ring and star topologies.
Hybrid topologies are most commonly useful in school settings, business, banks and universities. A hybrid topology is a very reliable and flexible network that users can easily use. But there are also some drawbacks to this topology. Damage to the backbone would cause to stop the whole network operations in hybrid topology. It is also highly expensive to create as it uses multiple network topologies to design hybrid topology.