Chapter 4 Types of Network

1. Chapter 4 Types of Network 4.1 LAN and WAN 4.2 Network Topology Bus Star Ring Mesh

2. Chapter 4 Types of Network 4.1 LANs, MANs and WANs • According to the geographical area covered, networks can be classified into • LAN • Local Area Network • MAN • Metropolitan Area Network • WAN • Wide Area Network • PAN • Personal Area Network

3. Chapter 4 Types of Network 4.1.1 LAN • Local Area Network (LAN) • formed by joining computers • in short distances • e.g. within the same building or within a campus • can be found in • home, offices, schools and universities, etc. • the technology used is mainly Ethernet • maximum effective length of UTP cable < 100 m • sometimes need fiber-optic cables

4. Chapter 4 Types of Network 4.1.1 LAN

5. Chapter 4 Types of Network 4.1.2 MAN • Metropolitan Area Network (MAN) • connects two or more LANs • within a specific geographic region • e.g. town/city • Each LAN is connected to a router • by long distance communication links • phone lines • microwave • fiber-optic cable • mainly private • users are required to login to use the service • except for those maintained by ISPs

6. Chapter 4 Types of Network 4.1.2 MAN

7. Chapter 4 Types of Network 4.1.3 WAN • Wide Area Network (WAN) • connects two or more LANs • distances measured in miles • across countries • by routers and communication links • Large companies: • private WANs • each branch form a LAN • linked together to form the WAN • The Internet • public WAN • supported by ISPs all over the world

8. Chapter 4 Types of Network 4.1.3 WAN

9. Chapter 4 Types of Network PAN • Personal Area Network (PAN) • linking mobile devices to a computer • Mainly BlueTooth

10. Chapter 4 Types of Network 4.1.4 Users’ View • Users • cannot easily distinguish between LAN, MAN and WAN • because • they look and operate in similar way

11. Chapter 4 Types of Network 4.2 Network Topology • Network topology • the shape of the logical linking of devices on a network • Common topologies • bus • star • ring

12. Chapter 4 Types of Network 4.2.1 Bus Topology (1/2) • Bus topology • consists of a long cable • to link the devices on the network • shared medium • usually a coaxial cable • Adv: • easy to install • least amount of cable • Disadv: • difficult to trouble-shoot • main cable fails → entire network fails • Typical examples • Ethernet 10Base-2, 10Base-5

13. Chapter 4 Types of Network 4.2.1 Bus Topology (2/2)

14. Chapter 4 Types of Network 4.2.2 Star Topology (1/2) • Star topology • consists of a cable concentrator • hub/switch • all data transfer pass through • Adv. • easy to maintain • flexible in adding or removing nodes • failure of a node will not affect whole network • Disadv. • hub fails → entire network fails • largest amount of cables • hub-based can be deteriorate if the network grows • Examples: • Almost all Ethernet networks & Wireless LAN • except for the old 10Base-2 and 10Base-5

15. Chapter 4 Types of Network 4.2.2 Star Topology (2/2)

16. Chapter 4 Types of Network 4.2.3 Ring Topology (1/3) • Ring topology • connects devices in a closed ring • Data travels in one direction • until it reaches the destination • or returns to the sender • Adv. • can support large number of nodes • Disadv. • a node fails → entire network fails • expensive • Examples: • Token Ring -- common in mainframe systems

17. Chapter 4 Types of Network 4.2.3 Ring Topology (2/3)

18. Chapter 4 Types of Network 4.2.3 Ring Topology (3/3) • Physical Wiring of a ring network • nodes are connected to a central device • called Multistation Access Unit (MAU) • cables are physically wired in a star

19. Chapter 4 Types of Network 4.2.4 Comparison between Topologies

20. Chapter 4 Types of Network 4.2.5 Mesh Topology • Mesh topology • each computer connects to all other computers • most expensive • redundancy – fault-tolerant