Common Devices used in Networking
Some of the common devices that are used in networking are; Repeaters, Extenders, Splitters, Terminators, Hubs, Switch's and Routers. Lets look at them in details.
Repeater -
A Repeater is a communication device that retransmits the weak signals with greater power. It receives the signals over the wireless, optical transmission and network cable mediums such as copper wire, UTP/STP and fiber optic cables and regenerates the analog or digital signals. This device is used to boost the signals in a co-axial cable only. On a single cable you can connect upto a maximum of 4 repeaters.
Some of the common devices that are used in networking are; Repeaters, Extenders, Splitters, Terminators, Hubs, Switch's and Routers. Lets look at them in details.
Repeater -
A Repeater is a communication device that retransmits the weak signals with greater power. It receives the signals over the wireless, optical transmission and network cable mediums such as copper wire, UTP/STP and fiber optic cables and regenerates the analog or digital signals. This device is used to boost the signals in a co-axial cable only. On a single cable you can connect upto a maximum of 4 repeaters.
Extender -
An Ethernet extender (also Network Extender) is any device used to extend an Ethernet segment beyond its normal distance limitation which is approximately 100 metres (330 ft) for most common forms of twisted pair Ethernet.
Splitter -
Splitters are used with UTP cables. These devices are normally connected to the back of a PC to which you can connect two UTP cables.
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| Splitter that goes in the back of a PC. |
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| These type of splitters are used to split a single Ethernet cable. |
Terminator -
A Terminator a device attached to the end-points of a bus network or daisy-chain. The purpose of the terminator is to absorb signals so that they do not reflect back down the line. If the signals reflect back down the line it will lead to collision thus resulting in system hang or traffic.
A Terminator a device attached to the end-points of a bus network or daisy-chain. The purpose of the terminator is to absorb signals so that they do not reflect back down the line. If the signals reflect back down the line it will lead to collision thus resulting in system hang or traffic.
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| Terminator |
Hub (aka Multi-Port Repeater) -
A Hub is a central connecting device in a computer network. There are two types of a hub i.e. active hub and passive hub. Every computer is directly connected with the hub. When data packets arrives at hub, it broadcast them to all the LAN cards in a network and the destined recipient picks them and all other computers discard the data packets. Hub has five, eight, sixteen and more ports and one port is known as uplink port, which is used to connect with the next hub. A Hub works at a speed of 10Mbps.
There are three broad categories of hubs if we compare them on technical bases. Passive hubs, active hubs and intelligent hubs are three kinds of hubs most frequently used. Hubs are not often preferably used because they are considered passive devices, which do not respond to the electrical signals. Such hubs which are not capable of regenerating electrical signals to efficiently transfer data packets are known as Passive hubs. Passive hubs are often termed as concentrators. More recently there are hubs available in the market which can perform actively. Multi Port Repeaters which can amplify the electric signals to deliver packet of data are known as active hubs. When active hubs are developed more to be used by companies they are known as intelligent hubs. The purpose of these hubs is to preserve the space in an operation room or office. Various hubs are set one over the other to allow enough space for the human working. Intelligent hubs can also back up media and multiple protocols.
Switch (aka Intelligent Hub) -
A Switch is an intelligent device that maps the IP address with the MAC address of the LAN card. Unlike the hubs, a switch does not broadcast the data to all the computers, it sends the data packets only to the destined computer. Switches are used in the LAN, MAN and WAN.
A Hub works at 10Mbps and is a Single Transmission Media, as only two systems connected to a Hub can communicate at a time. If another system connected to the Hub tries to communicate at the same time, it will result in a collision.
A Switch works at 10Mbps/100Mbps/1000Mbps (can sometimes work at 10000Mpbs) and is a Multiple Transmission Media, because all the systems connected to a Switch will be able to communicate simultaneously.
Router -
A Router is a communication device that is used to connect two logically and physically different networks, two LANs, two WANs and a LAN with WAN. The main function of the router is to sorting and the distribution of the data packets to their destinations based on their IP addresses. Cisco routers are widely used in the world. Every router has routing software, which is known as IOS. Router operates at the network layer of the OSI model. Router does not broadcast the data packets.
Note: Other Router manufacturing companies are Extreame, Checkpoint, Juniper, Huawe There are different series in a router. The most commonly used ones are the 2500 and 2600 series.
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| A CISCO 2501 series router (back). |
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| A CISCO 2601 series router (back). |
How do Hubs, Switches and Routers differ?
Hubs, switches and routers are all used to connect computers together on a network, but each of them has different capabilities.
Hubs
Hubs enable computers on a network to communicate. Each computer plugs into the hub with an Ethernet cable, and information sent from one computer to another passes through the hub. A hub can't identify the source or intended destination of the information it receives, so it sends the information to all of the computers connected to it, including the one that sent it. A hub can send or receive information, but it can't do both at the same time. This makes hubs slower than switches. Hubs are the least complex and the least expensive of these devices.
Switches
Switches work the same way as hubs, but they can identify the intended destination of the information that they receive, so they send that information to only the computers that are supposed to receive it. Switches can send and receive information at the same time, so they can send information faster than hubs can. If your home network has four or more computers, or you want to use your network for activities that require passing a lot of information between computers (such as playing network games or sharing music), you should probably use a switch instead of a hub. Switches cost a little more than hubs.
Routers
Routers enable computers to communicate and they can pass information between two networks—such as between your home network and the Internet. This capability to direct network traffic is what gives the router its name. Routers can be wired (using Ethernet cables) or wireless. If you just want to connect your computers, hubs and switches work well; however, if you want to give all of your computers access to the Internet using one modem, use a router or a modem with a built-in router. Routers also typically provide built-in security, such as a firewall. Routers are more expensive than hubs and switches.
