1. Basic Concepts

2. Line Configuration Line Configuration Topology Topology Transmission Mode Transmission Mode Categories of Networks Categories of Networks Internetworks Internetworks

3. Line Configuration The way two or more communication devices attach to the link The way two or more communication devices attach to the link The link = physical pathway that transfers data from one device to another The link = physical pathway that transfers data from one device to another Point-to-Point Point-to-Point Multipoint Multipoint

4. Point-to-Point workstation server link

5. Multipoint server workstation Capacity of the channel is shared spatially shared line several devices can use the link simultaneously time-shared lineusers must take turn

6. Basic Concepts Line Configuration Line Configuration Topology Topology Transmission Mode Transmission Mode Categories of Networks Categories of Networks Internetworks Internetworks

7. Topology Topology = the way a network is laid out Topology = the way a network is laid out Physically Physically Logically Logically Mesh Mesh Star Star Tree Tree Bus Bus Ring Ring

8. Relationship Status Peer-to-peer Peer-to-peer The devices share the link equally The devices share the link equally Primary-secondary Primary-secondary One device control traffic and the other must transmit through it One device control traffic and the other must transmit through it Ring and mesh topology  peer-to-peer transmission Ring and mesh topology  peer-to-peer transmission Star and tree topology  primary-secondary Star and tree topology  primary-secondary Bus  both Bus  both

9. Mesh Advantages: no shared link, each communication carries its own data load robust – if one link is unusable, there are still other links to use privacy and security fault identification and fault isolation -- easy

10. Mesh Disadvantages Disadvantages Requires many cables, ports, hardware Requires many cables, ports, hardware N devices require N devices require N(N-1)/2 physical channels N(N-1)/2 physical channels N-1 I/O ports for each device N-1 I/O ports for each device

11. Star hub Central control Each device needs only one link, one I/O port Easy to install, reconfigure Less cables Fault detection /isolation  easy robust

12. Tree hub Central control hub (Active hub)

13. Bus Tap Cable end Tap Drop line backbone

14. Bus Advantages easy to install less cables Disadvantages fault isolation is difficult difficult to add new devices

18. Basic Concepts Line Configuration Line Configuration Topology Topology Transmission Mode Transmission Mode Categories of Networks Categories of Networks Internetworks Internetworks

19. Transmission Mode Defines the direction of signal flow between two linked devices Defines the direction of signal flow between two linked devices Three types Three types Simplex Simplex Half-duplex Half-duplex Full-duplex Full-duplex

20. Transmission Mode Simplex Simplex Unidirectional, like a one way street Unidirectional, like a one way street Only one device can transmit, the other only receives Only one device can transmit, the other only receives monitor server Direction of data

21. Transmission Mode Half-duplex Half-duplex Each station can both transmit and receive but not at the same time Each station can both transmit and receive but not at the same time When one device is sending, the other can only receive When one device is sending, the other can only receive E.g. Walkie-talkie E.g. Walkie-talkie Direction of data at time 2 Direction of data at time 1

22. Transmission Mode Full-duplex Full-duplex Both stations can transmit and receive simultaneously Both stations can transmit and receive simultaneously E.g. telephone network E.g. telephone network Direction of data at the time

23. Basic Concepts Line Configuration Line Configuration Topology Topology Transmission Mode Transmission Mode Categories of Networks Categories of Networks Internetworks Internetworks

24. Categories of Networks LAN (Local Area Network) LAN (Local Area Network) MAN (Metropolitan Area Network) MAN (Metropolitan Area Network) WAN (Wide Area Network) WAN (Wide Area Network)

25. Internetworks Two or more networks are connected Two or more networks are connected