Networks

Networks

1. The size of the networks

   • LAN
     • In these networks the computers are very close to each others, like the rooms of a house.
   • MAN
     • They are made up of computers distributed throughout a city.
   • WAN
     • They are made of computers spread throughout a country, a continent or the entire world.

2. Whose networks are they?

   • Public networks
     • Whose access is public and global.
   • Private networks
     • Whose access is restricted to the owner or users who use them ( They are mostly LAN networks )
   • VPN
     • They are a type of networksresulting from the interconnection of several private networks with each other, taking advantage of the infrastructure of a global network.

3. Peer to peer networks and client server networks

   • That can be organised in two types.
   • Client server networks
   • Point to point networks

4. The topologies

   • The topology is the way in which w can connect the different workstations and the different transmission media within a local area network. 
   • Bus topology
     • Bus networks share the same transmission channel, called the bus.
   • Ring topology
     • In this type of network, all computers are connected to a specific device that is responsible for transmitting information.
   • Star topology
     • It's a closed networks in which the equipment is located in a similar way to that of the bus.

5. The ethernet standard

   • It's called ethernet the conexion which uses a cable as a transmission line.

6. What is a computer network?

   • A computer network is a set of computers which are connected to each other with the purpose of share information.

7. Wired networks.

   • In this type of network, the information travels in form of waves encapsulated within a cable
   • The twisted by cable
   • Fibred optics

8. Wireless networks

   • It provides a very flexible communication system by eliminating completely the use of cables
   • Wi-Fi technology
   • Bluetooth technology
   • Other wireless media

9. Devices on a Lan networks

   • Network cards are the devices that connect computers to the networks. They are usually integrated in motherboards nowaday.
   • The network card
   • The switch
   • The router

10. The TCP/ IP communication protocol

    • The protocol of a network is the software necessary for two computers on a network to communicate with each other.
    • TCP / IP
    • IP adress
    • Classes of IP adress
    • Routing and gateway

11. TCP / ICP Sevices.

    • Knowing the different IP numbers of Internet servers is too complicated. The DNS is a system similar to the phone book. Instead of remembering complicated IP addresses, we can connect to a host using its DNS name, more easily.
    • The DHCP service
    • Fixed port services: HTTP, FTP, POP3, etc.

12. Domain workgroups and networks.

    • Local networks can be classified from the point of view of their operation in peer-to-peer networks and client-server networks. There are workgroups, while the second model corresponds to domain networks.