Network Devices

Network Devices

Introduction:

Network devices are components used to connect computers or other electronic devices together so that they can share files or resources like printers or fax machines. Devices used to setup a Local Area Network (LAN) are the most common type of network devices used by the public. A LAN requires a hub, router, cabling or radio technology, network cards, and if online access is desired, a high-speed modem. Happily this is much less complicated than it might sound to someone new to networking.

In a network, one computer is designated as the server, and the others, clients. The server is connected to an external hub, which the clients are also connected to. Now that the computers each have one foot in a common electronic door (the hub), they can use the hub to pass signals back and forth. To direct these signals, the hub contains a device known as a router. The router is the equivalent of an electronic traffic cop that handles data traffic between the computers. Some of the network devices are explained below:

1. MODERM

• It is stand for modulation and demodulation.
• It is device that modulates the data before data transmission and demodulates the same data with the same rule at the receiving end.
• It is used in multimedia networking and internet to transmit the data from copper wire.
• There are three types of modulation technique and they are :

       a. FSK ( Frequency Shift keying ) or FM (Frequency Modulate )
       b. ASK ( Amplitude Shift keying )
       c. PSk ( Phase Shift keying ) or PM ( Phase Modulate ).

Fig of MODERM

• The diagram is shown below:

Fig. of HUB

2. Switch/Hub

• It is a common network devices .
• It has multiple ports for connecting different computer on the network.
• It is used to split the networking media or provide multiple connection.
• It operate at physical layer of OSI model.
• It accepts data , amplify and then transmit.

3. Bridge

• It is a connecting devices that connect two or more hubs.
• It is a devices which cannot different network segments and passes data with the same communication protocol.
• It is more intelligent then hub because it maintain MAC ( Media Access Control ) address table in it and forward the data by looking into it.
• It reduce unnecessary data traffic problem by controlling broad casting.
• It operates at layer 2 ( Data  Link layer ) of OSI model.
• The diagram is shown below:

Fig of bridge

4. Router

• It is an electronic devices that intercept data on a computer network .
• It is also used to connect separate network and to access internet.
• It is similar to Bridge .
• It operates at 3 network layer of OSI model.
• The diagram is shown below:

Fig. of router

5. Repeater

• It operate at layer 1 ( physical layer ) of OSI model.
• It receive signal amplifies it and sends it forward.
• It increase the distance over which the network can be extended.
• The diagram is shown below:

Fig of repeater