Network topology

Computers talk using a special plan.

This plan shows how tools connect. One plan is where things sit. This is the physical plan. It uses wires or air.

Some use long glass strings. These carry light to send news. Another plan is how news moves. This is the logical plan. The news can move in a circle. It can also move in a star shape.

These plans help us share things.

Computers and other tools talk to each other in a network. A network topology is the plan for how these tools connect.

There are two ways to look at a network. The first is the physical topology. This is the actual way parts are placed. It shows where cables go and where tools sit.

Some networks use wires. One type uses glass threads called optical fiber. These carry light to send data very fast. Other networks use radio waves to talk through the air.

The second way is the logical topology. This is the way data moves from one tool to the next. The physical wires might look like a star, but the data might move in a ring.

Nodes are the points where the network connects to a tool. A node can be a computer or a small part that sends signals. These nodes use links to share information. These links can be metal wires or even light.

A network topology is the plan for how parts of a communication network are arranged.

It describes how devices connect to share information. These devices are called nodes. The connections between them are called links. Scientists use something called graph theory to model these systems. In this model, devices act as nodes and connections act as lines. This structure helps us understand everything from home computer networks to radio systems used for command and control.

There are two ways to look at these arrangements. The first is the physical topology. This is the actual placement of all the parts. It shows where devices sit and where cables are installed.

The second way is the logical topology. This describes how data flows from one device to the next. A network might look like a star shape physically, but the data might move in a ring shape logically. This means the path the information takes is different from the actual wires.

Many different types of links can be used to connect nodes. Some networks use electrical cables like Ethernet. Others use optical fiber, which is a thin glass thread. These fibers carry pulses of light to send data. Light is very fast and does not get interrupted by electrical noise.

You can also use wireless links like radio waves. These waves travel through the air to connect devices. Some systems even use a building's own power lines to send data.

Different technologies have different speeds and uses. Twisted-pair cabling uses copper wires twisted together to stop interference. These can reach speeds of 10 billion bits per second. Coaxial cable is often used for cable television. It can move data at 500 million bits per second. Optical fibers are even faster and can reach trillions of bits per second. They are used in huge undersea cables to connect different continents.

Even satellites in space help by relaying signals using microwaves.

Understanding topology helps us build better tools. For example, vehicles use Controller Area Networks to connect sensors and controllers. These usually use a physical bus topology. In a local area network, or LAN, nodes can be connected in a ring, bus, mesh, or star shape.

Some networks can even change their logical shape automatically. This happens by changing how routers and switches are set up. This flexibility helps keep our modern digital world running smoothly.

Network topology is the specific arrangement of elements within a communication network. These elements include nodes, which are connection points, and links, which are the connections between them.

This concept applies to many different systems. It can describe computer networks, industrial fieldbusses, or command and control radio networks. Scientists use graph theory to model these systems. In this mathematical model, communicating devices act as nodes. The connections between those devices are modeled as links or lines.

Understanding topology is essential for designing how information moves across the world.

There are two distinct ways to categorize network topology: physical and logical. Physical topology refers to the actual placement of components. This includes where devices are located and how cables are installed.

It is a primary concern of the physical layer of the OSI model. Logical topology, however, describes how data actually flows through the network. The logical path of information does not have to match the physical wiring. For example, a network might use a physical star topology. Yet, the data might move in a logical bus topology.

This distinction allows engineers to separate the hardware layout from the data movement rules.

Physical topologies come in several common shapes. In a local area network (LAN), nodes can be arranged in a ring, bus, mesh, or star.

A bus topology uses a single line to connect all devices. A star topology connects every node to a central point. A ring topology connects nodes in a continuous loop. Mesh topologies involve many interconnected links. Some systems, like Controller Area Networks in vehicles, use a physical bus topology. These networks connect controllers to sensors and actuators. The choice of topology depends on cost, control, and fault tolerance.

Links are the transmission media used to connect nodes. These media can be electrical cables, optical fibers, or radio waves.

Wired technologies include Ethernet, which is a widely adopted family of LAN technology. Ethernet can use copper or fiber cables. Twisted-pair cabling is the most common medium for telecommunications. It uses copper wires twisted into pairs to reduce crosstalk and electromagnetic induction.

Coaxial cable is another wired option, often used for cable television. It consists of a conductor surrounded by insulation and a conductive layer. These cables can reach speeds of over 500 million bits per second.

Optical fiber represents a much faster way to transmit data. An optical fiber is a thin glass thread. It carries pulses of light to represent data.

These fibers have very low transmission loss. They are also immune to electrical interference. Optical fibers can carry multiple wavelengths of light at once. This allows for data rates of up to trillions of bits per second. Because of this speed, they are used in undersea cables to connect continents. Wireless technologies offer a different kind of connectivity. These include terrestrial microwaves, which require line-of-sight, and communications satellites in geostationary orbit.

Satellites use microwave radio waves to relay voice, data, and TV signals.

Nodes serve as the connection points for these transmission media. A node is where the medium meets a transmitter or receiver.

While nodes are often computers, they can also be simple microcontrollers. Some nodes are designed to only transmit, while others can both transmit and receive. In a simple point-to-point topology, one transmitter connects to one receiver. In more complex systems, a single node might connect to many others on a single bus. Modern hardware like network interface controllers (NICs) helps manage these connections. These devices allow a computer to join a network and communicate effectively.

Topology connects to many broader scientific and engineering fields. It is deeply tied to media access control methods and protocols. Some advanced networks can even change their logical topology dynamically. This happens through configuration changes in routers and switches. The study of topology also touches on the OSI model, which organizes how different layers of communication work together. From the small scale of a printed circuit board to the massive scale of the interplanetary internet, topology defines the structure of our connected world.