CCNA English-01: Basic Networking

What is a network?

A network is when multiple computers are connected together to exchange information. A minimum of two computers are required for networking.

Types of networks:

Networks can generally be divided into three parts.

Local Area Network (LAN): A network consisting of different computers located in the middle of the same building is called Local Area Network. The data transfer speed of this network is 10 Mbps. The devices used in this network are a repeater, hub, network interface, etc.

Metropolitan Area Network (MAN): An interface consisting of several LANs located within the same city is called a metropolitan area network. Such a network can extend up to 50-65 miles. This network data transfer speed is a gigabit per second. Devices used in such networks are routers, switches, microwave antennas, etc.

WAN (Wide Area Network): A network formed with remote LANs is called a wide area network. The data transfer speed of such a network is from 56 kbps to 1.544 Mbps. The speed of the van is slowly changing. Devices used in such networks are routers, modems, WAN switches, etc.

Topology:

A topology is a catalog of how computers are connected to a network. Topology plays a special role in network design. Topology can be of different types such as bus topology, star topology, ring topology, mesh topology, etc. Below are the different topologies:

Network cable:

A network cable is a cable that is used to send data from one computer to another.

Different types of cables are used for networking. Such as:

Coaxial cable
Twisted pair cable
Fiber optic cable

Coaxial cable:

Coaxial cable is used in some local area networks. There are several types of coaxial cable. Such as- 50 ohms (RG-6, RG-11 RG-57), 65 ohms (RG-59), and 93 ohms (RG-72). The price of this cable is much lower. There is an EMI problem because copper is made.

Twisted pair cable

Twisted pair cables are of two types.

Shielded twisted pair cable
Unshielded twisted pair cable

Shielded twisted pair cable

Shielded twisted pair cable has a twisted pair inside a tight cover. As a result, the electric interference is much less. The data transfer speed of this cable is 500 Mbps.

Unshielded twisted pair cable

Unshielded twisted pair cable has no extra shielding on the outside of the pair, only a plastic jacket on the outside. The data transfer rate of this cable is 16 Mbps.

Fiber optic cable

In this cable, glass is used as media rather than copper wire. As a result, there is no electromagnetic interference. The data transmission speed of this cable is much higher. There are two types of fiber optic cable. Single-mode fiber and multimode fiber. The main disadvantage is that the price is too high and difficult to install.

Repeater:

A repeater is a device used to amplify a signal. If you amplify that signal using a repeater before you have covered a distance of 185 meters, it can go a further 175 meters. It works on the physical layer of the OSI model.

Hub

A hub is a repeater with multiple ports. It works with electric signals. The hub does not have a headache with the network address or the MAC address of the network adapter. It also works on the physical layer of the OSI model.

Bridge

A bridge is a device that connects multiple network segments. It creates bridging tables for keeping track of different devices in each segment. It works on the data link layer of the OSI model.

Switch

A switch is a bridge with multiple ports. It stores a list of the MAC addresses of each node. It works on the data link layer of the OSI model.

Router

Routing is the process of sending data from one network to another. And the device used for routing is the router. It works on the network layer of the OSI model.