network fundamentals

Network:

        When two or more nodes connected to each other is called Network.

Networking:

        A group of devices connected to each other and follow similar usage of protocols to communicate, share information is called networking.

• networks works by following some standards and protocols

Protocol:

    Set of instructions.

node:

    Are the devices that help control the traffic flowing through a network. nodes include workstations, servers and end devices.

Network Types

SOHO network:

    Networks usually have a few nodes is called a SOHO network. SOHO means small office home office these networks typically have a couple of computers, a printer, few phones and tablets.

Enterprise Network:

    Many devices link together is called Enterprise network, It may cover several floors in a building there may also several office buildings across the city or countries.

Service provider network:

    The internet provider has a very large network this is called a service provider network. Not only do they provide internet access they also offer services to connect their customers together.

LAN:

    When devices are connected in one physical area, like an office building, a school or home is called LAN or Local area network.

MAN:

    Metropolitan area network, It is a network which is across a large geographical area such as an entire city or college campus.

WAN:

    Wide area network, occupies a very large area such as an entire country or the world. The internet is the best example for public WAN.

Types of communication in networking

Unicast: one to one communication.

Multicast: one to many, but not to everyone.

Broadcast: one to all.

Network Components

1.End devices:  A source or destination devices in a network system

    Host: 

        Any device that can be a client, server or any other type of computer.

    Client: 

        Clients are host devices that have software installed that enables the hosts to request and                         display information from servers.

    Servers: 

        Are the hosts that equipped with specific software and/or hardware that enables it to offer                        services to client devices.

    NIC:

           Network interface card is a hardware component which helps to connect over the internet.

     Printers:

            Are the output devices basically which prints hardcopy of data that is stored in computers or                    any other devices.

    Etc.

2.Intermediate devices

    Hub:

        Is a central device which connects all other nodes for communication. hubs don't have the                       intelligence to find out the best path for data packets.

        types:

            Active hub

            passive hub

            intelligent hub

    

    Switch:

            Switch is a network device which is used to connect different hosts.

• Switch is intelliegent devic and It can understand MAC address and stores all the entries in CAM ( content addressable memory )
• Full duplex ( Both sender and reciever can send data each other simultaneously)

      L2 switch : It is a network device which works on data link layer and it is used to connect         different host in the LAN

     L3 siwtch : L3 switch has both router and switch functionality , it can act as switch connect     devices that are in the same subnet and it has ip routing intellegence built in to act as             router. and also this L3switches are used to connect L2 switches.   

    

     Router:

            Routers are the network devices used to connect different networks.

    

    firewall:

             A Firewall is a network security device that monitor and control incoming and outgoing                        network traffic based on predetermined rules.

3.Transmission medium:

       It is a communication channel that carries data packets from the sender to the receiver in the form         of bits.

        Bandwidth :

                Bandwidth is a measure how much data a link can handle, its capacity.

       Throughput :

                Throughput is the actual amount of data that is sent/received over the link.