Networking devices also known as Networking Hardware or networking equipment. There is no fixed word for them and you can call whatever you want! You must have heard names of many networking devices like Router, Switch, Hub, etc. In this post we will discuss some of these networking devices and their purposes.

First, let me tell you that all these networking devices have same meaning but have different purposes. All these devices are meant to forward the data coming from host device to destination device. But how they transfer/forward data, the mechanism is different for all devices. Their mechanism depends on the type of communication. For example, their are 3 types of communication in networking:

1- Broadcast:

Broadcast means sending/forwarding data to all the devices connecting to network. For example, News are always broadcasted. In simple words, getting a piece of information and spreading it to all connections. It works on “1-to-ALL” terminology.

2- Multicast:

Multicast means sending/forwarding data to some devices like a group of devices. For example, I work in a company and I want to share some information with only one department then this type of communication is called Multicasting. It works on “1-to-‘X'” terminology, where X is list of specific devices or group of devices.

3- Unicast:

Unicast means sending/forwarding data to only one device. For example, I have some some information and I want to share it with only one person, then this type of communication is called as Unicast communication. It works on “one-to-one” terminology.

So, now coming towards the networking devices, following is the list of some networking devices used commonly around us, followed by their explanation.

Modem:

Have you ever noticed that phone cables coming to our homes are also used as a Internet connection? How is it happening? Phone Cable carries analog signal whereas our computer can only read digital signals. Here is the place for modem. Whenever you want to use phone cable as Internet connection, you want modem. Now, many of you will think modem is used to convert analog signal to digital signal then you are wrong!  Modem is used for modulation and demodulation of signals.

Let’s suppose you want to transfer a paper from one place to another. If you throw paper it won’t be able to travel that distance. But if you wrap a marker in paper and then throw the paper, paper will be able to cover the distance required. Wraping a marker in paper is called modulation. But once paper has reached its place, marker should be removed in order to get the original data. This is called demodulation. These tasks, providing appropriate carrier fro transferring data, is done by modem.

Hub:

Hub is a networking device which is used to connect multiple devices for sharing information or data. According to OSI Reference Model, Hub is Layer 1 networking device. Hub is also called as Broadcast device. The main purpose of hub is to receive data and forward it to all the devices connected to hub. Hub us just a box having an ability to transfer the received data to all the devices. From above information, we can say that, hub follows the broadcast communication type. Hub transfers data in the form of packets.

Whenever a hub receives a data packet, it copies it and forward to all of its connected ports. Because of this mechanism, hub is not considered secured and is not used mainly in Enterprises. For example, one wants to share a piece of information to one person but hub is used as a connecting device then that piece of information will be forwarded to all devices and information won’t be secured anymore.

Switch:

Network switch is another device used for connected different devices. This device works on Layer 2 of OSI Reference Model. Switches can be used for both Local Area Network and Wide Area Network. But switch for LAN will be different from switch for WAN. Switch is similar to Hub but we can say that switch is somehow intelligent than hub. Hub forwards the packets as it is to all the connected devices but switch first sort  the packets and then forwards it to other devices according to MAC Addresses.

When a switch is configured and a device is connected to switch, forwarding table is generated in switch which has all the required content address memory. When a packet is received by switch it sorts the packets with respect to destination MAC Addresses and then forwards it to that device.

Router:

Most commonly known and used device! Everyone has definitely heard about the ROUTER. Router is Layer 3 device of OSI Reference Model. Router is also called as Unicast device for the data. It is similar to networking switch but the difference is, router sorts the data according to network addresses and then forwards them to the requested device. So, we can say that router transfers the data from one network to the other network. You can think of a router as a traffic police who directs different network traffic to different directions.

Within a network, LAN is used and outside a network, WAN is used. So, router is used to transfer in LAN and WAN both. In short, router integrates LAN and WAN.

Bridge:

A bridge is a device used for connecting two networks. A bridge detects the incoming traffic from one network and further decides whether to forward the frames or discard them. A bridge first stores all the packets and then forward them to the desired device. The difference between router and bridge is, router sorts and forwards the data, whereas, bridge stores the data first and then forwards it.

Repeater:

Every medium, Ethernet cable or Fiber Optics, has a limitation that they cannot carry the signal for long distances. After some distance signal should be retransmitted or amplified. For this purpose, repeater is used. Repeater can be called as signal amplifier.

For example, if you want to connect two PCs by single wire and distance is more than miles then you should use repeater, if you want original quality of signal. Repeater receives the signal and then again forwards it with high intensity and power.

These are few devices used commonly in industry. Every person entering in networking field should have know how of all these devices.

I hope, this will be helpful for you!

Please comment, if I missed anything or misstated anything.

Thanks!