Network topology refers to the geometric arrangement of links and nodes in a computing network. Alternately, network topology may describe how the data is transferred between these nodes. Show
There are two types of network topologies: physical and logical. Physical topology emphasizes the physical layout of the connected devices and nodes, while the logical topology focuses on the pattern of data transfer between network nodes. Advertisement Techopedia Explains Network TopologyThe physical and logical network topologies of a network do not necessarily have to be identical. However, both physical and network topologies can be categorized into five basic models:
Network Topologies and the Physical NetworkThe earlier physical networks of computing at the end of the 20th century used these methods above to create these topologies explicitly. It’s fairly simple to envision the individual workstations being connected through Ethernet, or later through Wi-Fi, in a ring, star, tree, or bus setup, or any of the other topologies mentioned. However, figuring out the best topology involves a detailed look at the goals and objectives and other setup factors for a given network. Topologies and the Virtual NetworkAs the cloud became a place to keep data, run networks and deliver end-user services, the concept of virtualization took over the world of modern computing. In a virtualized network, those traditional physical pieces of hardware are to an extent replaced by logical partitioned resources often called “virtual machines” that parcel out CPU and memory accordingly. With that in mind, the traditional network topologies might still be used, but they’re more logical than they are a way to characterize hardware setups. In other words, the logical topologies are built “on top of” the physical topologies that connect hardware. In this type of modern network, the mesh topology, or a vibrant tree topology, would perhaps be more applicable and more popular. Where specific network destinations receive addresses and are dealt with as though they are individual nodes of the network, they're more likely to be connected to many other nodes than they would have been in the early days when that required individual physical linking. In addition, new best practices have evolved: for physical topologies, that includes assessing the capability of systems to offer features like high bandwidth, large bisection capacities, and a greater number of alternative data paths. In the world of logical topologies, experts have begun to talk about “topology switching” as a means of dynamic customization for VLANs and other network setups. Network Topology and OpacityIn the most modern systems, networks have become so complex that traditional topologies now apply in different ways. One of these phenomena is the use of opaque systems to foil hackers or outside cyberattacks. Some experts are now suggesting that by shielding the IP addresses and isolating different parts of the network into segments, companies can practice better cybersecurity hygiene. All of that continues to change how network topologies are used. Topology is derived from two Greek words topo and logy, where topo means 'place' and logy means 'study'. In computer networks, a topology is used to explain how a network is physically connected and the logical flow of information in the network. A topology mainly describes how devices are connected and interact with each other using communication links. In computer networks, there are mainly two types of topologies, they are:
Network topology defines the layout, virtual shape, or structure of the network, not only physically but also logically. A network can have one physical topology and multiple logical topologies at the same time. In this blog, we will mainly concentrate on physical topologies. We'll learn about different types of physical topologies, their advantages, and disadvantages. In a computer network, there are mainly six types of physical topology, they are:
Now let us learn these topologies one by one: Bus TopologyBus topology is the simplest kind of topology in which a common bus or channel is used for communication in the network. The bus is connected to various taps and droplines. Taps are the connectors, while droplines are the cables connecting the bus with the computer. In other words, there is only a single transmission line for all nodes. When a sender sends a message, all other computers can hear it, but only the receiver accepts it(verifying the mac address attached with the data frame) and others reject it. Bus technology is mainly suited for small networks like LAN, etc. In this topology, the bus acts as the backbone of the network, which joins every computer and peripherals in the network. Both ends of the shared channel have line terminators. The data is sent only in one direction and as soon as it reaches the end, the terminator removes the data from the communication line(to prevent signal bounce and data flow disruption). In a bus topology, each computer communicates to another computer on the network independently. Every computer can share the network's total bus capabilities. The devices share the responsibility for the flow of data from one point to the other in the network. For Example Ethernet cable, etc. Following are the advantages of Bus topology:
Following are the disadvantages of Bus topology:
Ring TopologyRing topology is a topology in which each computer is connected to exactly two other computers to form the ring. The message passing is unidirectional and circular in nature. This network topology is deterministic in nature, i.e., each computer is given access for transmission at a fixed time interval. All the nodes are connected in a closed-loop. This topology mainly works on a token-based system and the token travels in a loop in one specific direction. In a ring topology, if a token is free then the node can capture the token and attach the data and destination address to the token, and then leaves the token for communication. When this token reaches the destination node, the data is removed by the receiver and the token is made free to carry the next data. For Example, Token Ring, etc. Following are the advantages of Ring topology:
Following are the disadvantages of Ring topology:
Star TopologyStar topology is a computer network topology in which all the nodes are connected to a centralized hub. The hub or switch acts as a middleware between the nodes. Any node requesting for service or providing service, first contact the hub for communication. The central device(hub or switch) has point to point communication link(the dedicated link between the devices which can not be accessed by some other computer) with the devices. The central device then broadcast or unicast the message based on the central device used. The hub broadcasts the message, while the switch unicasts the messages by maintaining a switch table. Broadcasting increases unnecessary data traffic in the network. In a star topology, hub and switch act as a server, and the other connected devices act as clients. Only one input-output port and one cable are required to connect a node to the central device. This topology is better in terms of security because the data does not pass through every node. For Example High-Speed LAN, etc. Following are the advantages of Star topology:
Following are the disadvantages of Star topology:
Mesh TopologyMesh topology is a computer network topology in which nodes are interconnected with each other. In other words, direct communication takes place between the nodes in the network. There are mainly two types of Mesh:
In a fully connected mesh topology, each device has a point to point link with every other device in the network. If there are 'n' devices in the network, then each device has exactly '(n-1)' input-output ports and communication links. These links are simplex links, i.e., the data moves only in one direction. A duplex link(in which data can travel in both the directions simultaneously) can replace two simplex links. If we are using simplex links, then the number of communication links will be 'n(n-1)' for 'n' devices, while it is 'n(n-1)/2' if we are using duplex links in the mesh topology. For Example, the Internet(WAN), etc. Following are the advantages of Mesh topology:
Following are the disadvantages of Mesh topology:
5. Tree Topology:Tree topology is a computer network topology in which all the nodes are directly or indirectly connected to the main bus cable. Tree topology is a combination of Bus and Star topology. In a tree topology, the whole network is divided into segments, which can be easily managed and maintained. There is a main hub and all the other sub-hubs are connected to each other in this topology. Following are the advantages of Tree topology:
Following are the disadvantages of Tree topology:
Hybrid Topology:A Hybrid topology is a computer topology which is a combination of two or more topologies. In practical use, they are the most widely used. In this topology, all topologies are interconnected according to the needs to form a hybrid. All the good features of each topology can be used to make an efficient hybrid topology. Following are the advantages of Hybrid topology:
Following are the disadvantages of Hybrid topology:
Hence, after learning the various computer network topologies, we can conclude that some points need to be considered when selecting a physical topology:
This is all about the topology and its types in a computer network. Hope you learned something new today. That's it for this blog. What is called the arrangement of interconnecting devices on the network?Network topology is the arrangement of the elements (links, nodes, etc.) of a communication network.
What are 3 arrangements of a network?Topology refers to the geometric arrangement of devices on a network. Local Area Networks (LANs) appear in one of three topologies: linear, ring, or star.
What topology connects all devices to each other?The mesh topology has a unique network design in which each computer on the network connects to every other. It is develops a P2P (point-to-point) connection between all the devices of the network.
What are the two kinds of network arrangement?There are two types of network topologies: physical and logical. Physical topology emphasizes the physical layout of the connected devices and nodes, while the logical topology focuses on the pattern of data transfer between network nodes.
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