1. Networking Some of the basics

2. What is a Network Simply put, its two or more computer connected together through a communication medium. A communication medium is the form the connection takes e.g. Ethernet cable, wireless network Its purpose is to send and receive data and share/use resources.

3. Quick questions What’s a Network? Name a Communication medium What’s a resource? Name 3 resources:

4. Key parts of a network Server- A computer(s) that provides the services to any other computer on the network. Client- The other computers on the network. These use the resources from the server. User- A person who uses a client to access resources on a network. Protocol- simply put, rules. A network can have many protocols the most common you will come across is IP(internet protocol).

5. Why use Networks? AdvantagesDisadvantages Sharing resources saves money Purchasing the communication media (equipment) is expensive. (servers) Security improved, users can not see each others work as each user has their own file system. Managing a large network is complicated. Data is easy to back up as it is all stored on the file server Security- Hackers and viruses can infiltrate the network more easily.

6. There are different types of networks Bus Topology Ring Topology Star Topology Topology- The mathematical study of shapes and spaces. In networking it means how we organise our network elements which we represent in shapes, see the link?

7. Bus Topology All clients, servers and resources are connected to one cable (the bus). When a message is transmitted everyone on the bus receives it. Only one device accepts it and processes it. Node- a point of an intersection. Where network meets client.

8. Bus Topology AdvantagesDisadvantages Cheap and easy to install, just cables and terminators If bus fails it will pull the whole network down. As you add to bus the lower its performance becomes. Greater likelihood of data collisions. Security- all clients see the all datatransmitted Data collisions- The result when data packets are transmitted at the same time from two or more network devices. Data packets fragment meaning no one gets the message

9. Ring Topology Each device is connected to two other devices to form a ring. When message is sent, it goes in one direction to each device until received by intended recipient.

10. Ring Topology AdvantagesDisadvantages Data is transferred quickly as only flows in one direction, meaning no data collisions. If ring or any device fails then whole network fails. Security- some workstations will see data not intended for them.

11. Star Topology Most common especially in homes. Each device is individually connected to the switch or Hub. Switch- These are clever boxes that receive data packets from a client or server and send it onto it intended recipient. (keeps a record of each clients MAC address) Hub- especially stupid compared to a switch. These receive the data packets and copy it, then broadcasts to every client it is connected to.

12. Star Topology AdvantagesDisadvantages Very reliable. If one cable/device fails network can stay up. Can even help in finding said fail quickly. Expensive to install. Lots of cable and additional central device is needed such as switch or HUB. High performance as no data collisions happen- if switches are used performance boosted again. If the central device fails then anything connected to it does as well.

13. Questions from you?

14. Questions from me? What is a network? Summarise the bus, ring and star topology in 1minute. Tell me one advantage and disadvantage from each topology.