Open Socrative – Room 970781

1. Open Socrative – Room 970781

2. List as many network components as possible

3. Objectives • compare the role of the following network components: • switches, • hubs, • wireless access points, • network interface cards, • wireless network interface cards, • routers, • repeaters, • Bridges • servers (file, applications, mail, proxy, print, backup) • identify where their use would be appropriate;

10. Hub • Hub is the same as a switch but not as intelligent • Does not examine the packets but sends them to every port. • Data is filtered by recipient devices. • Data collisions slow network

11. Client Client Hub The hub is used to allow 4 computers to physically connect to the network. The hub is then connected to the server. Hub Server Client Client • The following diagram shows two hubs segmented using a bridge (see bridge). Four computers have direct access to the network, although only one hub has direct access to the server. Server Client Hub Bridge Hub Client Client Client

12. Switch • Connect several devices • Data packets are received and examined by the switch that then sends them to the correct port • Managed switches can be configured to control the flow of data (priority etc) • Technical to setup

13. Switch Print Server Printer Client Client Web Server Switch Server File Server Client • Four web designers share both large and small files. Sometimes they send and receive emails with videos attached, download animations, upload large web pages, save and retrieve large files and print various files. • A star topology was used because of its speed and security. • A switch was used as it can direct files efficiently by choosing the connections needed to make. This is especially useful when all four designers are accessing the network at the same time. • As the switch can make simultaneous connections. Mail Server Client

14. Router • Advanced version of a switch. It stores the address of devices connected to it and sends data to recipient devices on an efficient route • Normally connects LAN to WAN

15. NIC • Enables a computer to connect to a network • Integrated into motherboard • Each NIC has a MAC address

16. Wireless NIC • To communicate with a WAP you need a wireless NIC • Can be in the motherboard, external dongle, or adapter card • Different communication standards

17. WAP • This is a hub that communicates wirelessly • These then connect to a switch more commonly • Problems with hackers

18. Wireless Access Points Client A signal is broadcast out Client WAP Switch Client Client

19. Wireless Access Points Client Client WAP Switch Client Client

20. Wireless Access Points Client Client WAP Switch Client Client

21. Wireless Access Points Client Client WAP Switch Client Client

22. Wireless Access Points Client Client WAP Switch Client Client

23. Wireless Access Points Client Client WAP Switch Client Client

24. Wireless Access Points The wireless device broadcasts back! Any device in broadcast range could intercept it! Client Client WAP Switch Client Client Baddy Client!

25. Wireless Access Points Client Client WAP Switch Client Client Baddy Client!

26. Wireless Access Points Client Client WAP Switch Client Client Baddy Client!

27. Wireless Access Points Client Client WAP Switch Client Client Baddy Client!

28. Wireless Access Points Client Client WAP Switch Client Client Baddy Client!

29. Repeater • Strengthens signals • Receives the signal cleans it and re-amplifies. • Think at home about the wireless connection

30. Repeater Client Client Client Client Room 1 • Quicky What type of hardware could go where the question mark is? Discuss. Repeater Client Client Server ? Room 2

31. Bridge • Connects to LANS together • Different to router as does n ot store addresses of devices connected to it.

32. Segment 2 Bridge Segment 1 Client Client Client Bridge Port A Port B • Segments are simple parts of a whole network. • Networks often split into smaller segments to maximise network efficiency. • Computers that usually talk to each other are kept in the same network. This minimises the risk of packet collisions. • This is common place when businesses are split into departments. Computers in the sales department will be on one segment, where as the finance department will have computers in a different segment. But, they are still part of the same network. • The bridge will have ports so that it can forward any traffic to another segment if needed. The bridge also blocks communications. It will know which computers are in which segment. If a packet is sent to a computer in the same segment as its originator, it will be blocked from going to the other segments on the network. Client Client Client

33. Servers • Lots of different servers completing different jobs.

34. File server • Stores user data files. • Network Operating System (NOS) allows accounts to be set up. • Requires username and password. • Can only access your own files.

35. Application Server • Stores applications for use across networks. • The application server can be used in two ways: • For storing installation files which can easily be deployed across client machines. • Low network traffic but increase in required processing power at client side. • Allows applications that are installed on the server to be run by client from the server side. • High network traffic but less demand on processing at client side.

36. Mail server • Manages mail in and out of a network. • Checks income emails for viruses • Filters out SPAM emails • Provides central address book for the organisation • Sets email and inbox sizes • Useful for both internal and external email.

37. Proxy server • Used to cache web pages. • When a request is made to a web server, a web page is downloaded and displayed on the client’s computer. It is also stored or ‘cached’ on the proxy server. • Requests for the same page are then downloaded from a proxy server which is much quicker than downloading from the internet.

38. Proxy server (cont.) • Also act as a security buffer. • Clients make a request for a file on a file server. • The proxy intercepts the request and checks the client’s authenticity. • Checks validity of user and they have authorisation to receive a file. • Proxy then requests the file from the file server and forwards it back to the client. • The client never has direct access to the file server.

39. Print server • Allows access to a shared printer. • Usually come with spooler software. • Spoolers collect jobs that have been sent to a printer, puts them in a queue, and then forwards the print queue to the printer. • Printers work much slower than a computer. This is why we use a spool. • Computers would slow down if each file was sent to a printer as the computer would have to wait for the printer to catch up with it.

40. Backup Server • The backup server backs up all data on the network. • If all users save data on the server, the server can automatically back-up files over night. • This means that if data is lost it can be recovered. • It may not be the most up to date version but it is better than having to start again. • It will usually make use of tape drives.