Content:
- Introduction:
- Modem
- Ethernet Card
- RJ45
- Repeater
- Hub
- Switch
- Router
- Gateway
Introduction to Network Device:
To communicate data through different transmission media and to configure networks with different functionality, we require different devices like Modem, Hub, Switch, Repeater, Router, Gateway, etc.
Modem
Modem stands for ‘MOdulator DEModulator’. It refers to a device used for conversion between analog signals and digital bits. There are modems connected to both the source and destination nodes. The modem at the sender’s end acts as a modulator that converts the digital data into analog signals. The modem at the receiver’s end acts as a demodulator that converts the analog signals into digital data for the destination node to understand.
Ethernet Card:
Ethernet card, also known as Network Interface Card (NIC card in short) is a network adapter used to set up a wired network. It acts as an interface between computer and the network. The Ethernet cable connects the computer to the network through NIC. Ethernet cards can support data transfer between 10 Mbps and 1 Gbps (1000 Mbps). Each NIC has a MAC address, which helps in uniquely identifying the computer on the network.
RJ45:
RJ 45 or Registered Jack-45 is an eight-pin connector that is used exclusively with Ethernet cables for networking. Basically, it is a small plastic plug that fits into RJ-45 jacks of theEthernet cards present in various computing devices.
Repeater
Signals lose their strength beyond this limit and become weak. In such conditions, original signals need to be regenerated. A repeater is an analog device that works with signals on the cables to which it is connected. The weakened signal appearing on the cable is regenerated and put back on the cable by a repeater.
Hub:
An Ethernet hub is a network device used to connect different devices through wires to one network. Data arriving on any of the lines are sent out on all the others. The limitation of Hub is that if data from two devices come at the same time, they will collide.
Switch:
A switch is a networking device that plays a central role in a Local Area Network (LAN). Like a hub, a network switch is used to connect multiple computers or communicating devices. When data arrives, the switch extracts the destination address from the data packet and looks it up in a table to see where to send the packet. Thus, it sends signals to only selected devices instead of sending to all. It can forward multiple packets at the same time. Hence switch is known as smart hub
Router
A router is a network device that can receive the data, analyse it and transmit it to other networks. A router connects a local area network to the internet. Compared to a hub or a switch, a router has advanced capabilities as it can analyse the data being carried over a network, decide/alter how it is packaged, and send it to another network of a different type. A router can be wired or wireless
Gateway
A gateway is a network node(Device) used in telecommunications that connects two networks with different transmission protocols together. Gateways serve as an entry and exit point for a network as all data must pass through or communicate with the gateway prior to being routed. A gateway can be implemented completely in software, hardware, or a combination of both
Reference:
- NCERT Class 12 CS