Networks

Networks

1. LAN (Local Area Network)

   • It is a network confined to one location.
   • Its resources are only accessible for computers on that LAN

2. A Network is a group of connections together so that they can communicate.

3. WAN (Wide area network)

   • A wide area network is a network of LANs spanning across a wide area.
   • The internet is a WAN

4. Wired

   • Computers are connected with physical wires Any electric pules are sent through to transmit binary data

5. Wireless

   • Radio waves are used to transmit binary data so no physical connection is needed

6. Topologies

   • Bus
     • A single cable connects all the computers. All of the clients and servers connect to this cable. Terminators are attached to each end of the cable
   • Ring Network
     • Each computer is connected to two other computers in a ring formation. Each computer receives signals from one of its connected computers. If the data is for itself, it reads it, if not it transmits it to the next computer. The data travels round the ring in one direction until it reaches its intended recipient.
   • Star
     • All computers are connected to a central hub or switch. A hub sends each message to all the other computers. A switch checks the address of sends it only to the correct one
   • Mesh
     • Each computer is connected to one or more other computers. A full mesh had every computer connected to every other computer. A partial mesh had only some of the computers connected

7. Circuit Switching

   • The route is locked until the communication is complete. This means that for a large transmission, other transmission may be blocked for a long time.

8. Packet Switching

   • Each packet will likely take a different route to its destination. The packets will arrive in a different order to which they were sent. Each packet needs to be numbered so it can be re-assembled in the right order.