WHAT ARE THE DIFFERENT NETWORK DEVICES?

 

Networking hardware, also known as network equipment or computer networking devices, are electronic devices which are required for communication and interaction between devices on a computer network. Specifically, they mediate data transmission in a computer network. Units which are the last receiver or generate data are called hosts, end systems or data terminal equipment.

 

An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware device for connecting multiple Ethernet devices together and making them act as a single network segment. It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming. A hub works at the physical layer (layer 1) of the OSI model. A repeater hub also participates in collision detection, forwarding a jam signal to all ports if it detects a collision. In addition to standard 8P8C ("RJ45") ports, some hubs may also come with a BNC or an Attachment Unit Interface (AUI) connector to allow connection to legacy 10BASE2 or 10BASE5 network segments.

 

A network switch (also called switching hub, bridging hub, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device. Unlike repeater hubs, which broadcast the same data out of each port and let the devices pick out the data addressed to them, a network switch learns the identities of connected devices and then only forwards data to the port connected to the device to which it is addressed.

 

A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork (e.g. the Internet) until it reaches its destination node.

 

A network bridge is a computer networking device that creates a single aggregate network from multiple communication networks or network segments. This function is called network bridging. Bridging is distinct from routing. Routing allows multiple networks to communicate independently and yet remain separate, whereas bridging connects two separate networks as if they were a single network. In the OSI model, bridging is performed in the data link layer (layer 2). If one or more segments of the bridged network are wireless, the device is known as a wireless bridge.

 

A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network. Modern network interface controllers offer advanced features such as interrupt and DMA interfaces to the host processors, support for multiple receive and transmit queues, partitioning into multiple logical interfaces, and on-controller network traffic processing such as the TCP offload engine.

 

A modem also known as "Modulator-Demodulator." It is a hardware component that allows a computer or another device, such as a router or switch, to connect to the Internet. It converts or "modulates" an analog signal from a telephone or cable wire to digital data (1s and 0s) that a computer can recognize. The goal is to produce a signal that can be transmitted easily and decoded reliably to reproduce the original digital data.

 

A network transceiver also known as “ transmitter-receiver,” a device that both transmits and receives analog or digital signals. The term is used most frequently to describe the component in local-area networks (LANs) that actually applies signals onto the network wire and detects signals passing through the wire. On a LAN the transceiver is responsible to place signals onto the network media and also detecting incoming signals traveling through the same cable.

WHAT ARE THE TYPES OF NETWORK TOPOLOGY?

 

Network topology is the schematic description of the arrangement of the physical and logical elements of a communication network. The configuration, or topology, of a network is key to determining its performance. Network topology is the way a network is arranged, including the physical or logical description of how links and nodes are set up to relate to each other.

There are five types of topology in computer networks:

1.Mesh topology- A network setup where each computer and network device is interconnected with one another. This topology setup allows for most transmissions to be distributed even if one of the connections goes down. It is a topology commonly used for wireless networks.

Advantages of Mesh topology:

• Manages high amounts of traffic, because multiple devices can transmit data simultaneously.
• A failure of one device does not cause a break in the network or transmission of data.
• Adding additional devices does not disrupt data transmission between other devices.  

Disadvantages of Mesh topology:

• Each node needs to both send messages as well as act as a router, which causes the complexity of each node to go up pretty significantly. 
• This complicates your network planning, because you now have to deploy a piece of equipment just to get your messages properly routed in a reasonable amount of time.
• Because each node in a mesh has to act as an endpoint and a router, it has to draw more power to operate. Thus, if you have battery-powered, low-power nodes, a mesh may be difficult to deploy without a lot of network planning.

2. Star topology- A topology for a Local Area Network (LAN) in which all nodes are individually connected to a central connection point, like a hub or a switch. A star takes more cable than e.g. a bus, but the benefit is that if a cable fails, only one node will be brought down.

Advantages of Star topology:

• Easy to install and wire.
• No disruptions to the network when connecting or removing devices.
• Requires more cable length than a linear bus topology.
• If the connecting network device (network switch) fails, nodes attached are disabled and cannot participate in computer network communication.

Disadvantages of Star topology:

• it is expensive to install as this type of network uses the most cable (network cable is expensive)
• extra hardware is required (hubs or switches) which adds to cost.
• if a hub or switch fails, all the devices connected to it will have no network connection.

3.Bus topology- A topology for a Local Area Network (LAN) in which all the nodes are connected to a single cable. The cable to which the nodes connect is called a "backbone". If the backbone is broken, the entire segment fails.

Advantages of Bus topology:

• Easy to connect a computer or peripheral to a linear bus.
• Requires less cable length than a star topology.
• Entire network shuts down if there is a break in the main cable.
• Difficult to identify the problem if the entire network shuts down.
• Not meant to be used as a stand-alone solution.

Disadvantages of Bus topology:

• It can be difficult to identify the problems if the whole network goes down.
• It can be hard to troubleshoot individual device issues.
• Bus topology is not great for large networks.
• Terminators are required for both ends of the main cable.
• Additional devices slow the network down.

4.Ring topology- A network configuration where device connections create a circular data path. Each networked device is connected to two others, like points on a circle. Together, devices in a ring topology are referred to as a ring network.

Advantages of Ring topology

• All data flows in one direction, reducing the chance of packet collisions.
• A network server is not needed to control network connectivity between each workstation.
• Data can transfer between workstations at high speeds.

Disadvantages of Ring topology :

• Due to the Uni-directional Ring, a data packet (token) must have to pass through all the nodes.
• If one workstation shuts down, it affects whole network or if a node goes down entire network goes down.
• It is slower in performance as compared to the bus topology.
• It is Expensive.

5.Hybrid topology- A type of network topology that uses two or more differing network topologies. These topologies can include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology.

Advantages of Hybrid Topology :

• This type of topology combines the benefits of different types of topologies in one topology.
• Can be modified as per requirement.
• It is extremely flexible.
• It is very reliable.

Disadvantages of Hybrid Topology :

• It is a type of network expensive.
• Design of a hybrid network is very complex.
• There is change hardware in order to connect topology with another topology.
• Usually hybrid architectures are usually larger in scales so they requires a lot of cables in installation process.