CIE A Level Applied ICT Unit 7 - Computer Networks
- 1. Computer Networks 9713 A Level Applied ICT 19713 A Level Applied ICT - Unit 7
- 2. Network Types • LAN: Local Area Network • WLAN: Wireless Local Area Network • WAN: Wide Area Network 29713 A Level Applied ICT - Unit 7
- 3. LAN • Intranet • Local email • Business network Hardware requirements • PC • Hub • Switch • Router • Dedicated cabling • Server • Network card Software requirements • FTP • HTTP • Telnet • SSH • Router software 39713 A Level Applied ICT - Unit 7
- 4. WLAN 4 • Wi-Fi (IEEE 802.11 standards – b, g, n) • Infrared • Spread spectrum transmission (walkie-talkie) Used for: • Email • Business network 9713 A Level Applied ICT - Unit 7
- 5. WAN • Internet • Extranets • Email • Virtual private network (VPN) • Video conferencing • Business network • Telephone call centre • Booking system • Online shopping • Online banking Hardware requirements • PC • Modem • Hub • Switch • Router • Server • Proxy server • VPN 59713 A Level Applied ICT - Unit 7
- 6. Network Hub • Used to connect computers to server/computer • Not a very efficient network device as it sends data to all linked devices • Hubs may amplify received signal • Hubs work at MAC level (MAC - Media Access Control address of NIC) Switch • An advancement on a hub • It directs the data stream only to the addressed device • It prevents congestion on a segment of network • Switches use a list of device addresses • Redirects ‘ack’ packet (Acknowledgement packet) directly to sending computer • Switches also work at MAC level 9713 AS Applied ICT - Unit 5 6 Hardware devices
- 7. Network Router • Gateway device • Links LANs to make a WAN • Includes a firewall • Directs packets according to their IP address • Stores list of connected devices • Redirects packets to correct switch/hub • Translates protocols (between networks) - bridge 9713 AS Applied ICT - Unit 5 7 Hardware devices
- 8. Network Cabling can be twisted pair, coaxial or fibre optics Servers: • Link computers/store files/applications • Can be for storage, web, proxy, email, etc. Network interface card (NIC): • Allows the processor to connect to a server • Allocated IP address of the computer 9713 AS Applied ICT - Unit 5 8 Hardware devices
- 9. FTP – File Transfer Protocol Network protocol used to transfer files from one computer to another TCP- based network (as the Internet) HTTP – HyperText Transfer Protocol Foundation protocol of data communication for the World Wide Web Telnet • Used to gain access to another users computer/remote access to server • Used to transfer/access data • Requires a password login id • Lacks security • Uses TCP/IP protocol (as a lower level) Secure Shell (SSH) Network protocol for secure data communication via a secure channel 9713 AS Applied ICT - Unit 5 9 Network Protocols (Software)
- 10. • Ring • Bus • Star • Tree 10 Network Topology 9713 A Level Applied ICT - Unit 6
- 11. • Physical security –Locked room –Security guard • Software security 11 Network security 9713 A Level Applied ICT - Unit 6
- 12. Network security Software security: • Firewall • Digital certification • Encryption • Anti virus software • User ID • Password • Anti spam • Anti pop up software • Anti spyware software • Authentication techniques • Wired equivalent privacy (WEP) 129713 A Level Applied ICT - Unit 6
- 13. Electronic conferencing Types: • Video conferencing • Phone conferencing • Instant messaging Used in: • Business conferences • Linking schools • Research meetings 139713 A Level Applied ICT - Unit 6
- 14. Electronic conferencing Software requirements • Conference software • VOIP software • Instant messaging Hardware requirements • PC • Phone • Webcam • Microphone • Speakers 149713 A Level Applied ICT - Unit 6