1. Adapted from Tanenbaum's Slides for Computer Networks, 4e
Chapter 1
Introduction
Adapted from Tanenbaum's Slides for Computer Networks, 4e

2. Use Scenarios for Networks
Access to remote information
Person-to-person communication
Interactive entertainment
Electronic commerce

3. A network with two clients and one server.
Client-Server
A network with two clients and one server.

4. The client-server model involves requests and replies.

5. Home Network Applications
Access to remote information
Person-to-person communication
Interactive entertainment
Electronic commerce

6. Peer-to-Peer
In peer-to-peer system there are no fixed clients and servers.
Our main concern in this class: how do messages get from application on one machine to client or server or peer on another.
Beyond that lies distributed systems, CptS 464/564

7. Network Scale Terminology
Classification of interconnected processors by scale.

8. Network Links Two types of data transmission technology
Broadcast links
Point-to-point links

9. Local Area Networks
Three broadcast networks
(a) Bus
(b) Ring
(c) Star

10. Metropolitan Area Networks
A metropolitan area network based on cable TV.

11. Relation between hosts on LANs and the subnet.
Wide Area Networks
Relation between hosts on LANs and the subnet.
(Note: this use of subnet is uncommon these days. Network Backbone is more typical for a closely related concept.)

12. A stream of packets from sender to receiver.
Wide Area Networks (2)
A stream of packets from sender to receiver.
(Note: not all packets need to take the same path!)

13. Wireless Networks (a) Bluetooth or infrared personal network
(b) Wireless LAN (Wireless ethernet/WiFi)
(c) Wireless MAN (WiMax)

14. Amazing thing: all these technologies work together to interconnect computers around the world. How?

15. Network Software Protocol Hierarchies – the Layers
Design Issues for the Layers
Connection-Oriented and Connectionless Services
Service Primitives
The Relationship of Services to Protocols

16. Network Software Protocol Hierarchies – the abstract story
Layers, protocols, and interfaces.

17. Protocol Hierarchies (Example)
The philosopher-translator-secretary architecture.

18. Protocol Hierarchies (3)
Example information flow supporting virtual communication in layer 5.

19. Design Issues in each Layer
Addressing
Error Control
Flow Control
Multiplexing
Routing
And, relative to its neighbor layes, its Interface (or service description)

20. Six different types of service.
Example Services
Six different types of service.

21. Service Primitives
Five service primitives for implementing a simple connection-oriented service. Where are they implemented in the hierarchy?

22. Services to Protocols Relationship
The relationship between a service and a protocol.

23. Reference Models The OSI Reference Model The TCP/IP Reference Model
A Comparison of OSI and TCP/IP
A Critique of the OSI Model and Protocols
A Critique of the TCP/IP Reference Model

24. The OSI reference model.
Reference Models
The OSI reference model.

25. The TCP/IP reference model.
Reference Models (2)
The TCP/IP reference model.

26. Protocols and networks in the TCP/IP model initially.
Reference Models (3)
Protocols and networks in the TCP/IP model initially.

27. Comparing OSI and TCP/IP Models
Concepts central to the OSI model
Services
Interfaces
Protocols

28. A Critique of the OSI Model and Protocols
Why OSI did not take over the world
Bad timing
Bad technology
Bad implementations
Bad politics

29. The apocalypse of the two elephants.
Bad Timing
The apocalypse of the two elephants.

30. A Critique of the TCP/IP Reference Model
Problems:
Service, interface, and protocol not distinguished
Not a general model
Host-to-network “layer” not really a layer
No mention of physical and data link layers
Minor protocols deeply entrenched, hard to replace

31. The hybrid reference model to be used in this book.
Hybrid Model
The hybrid reference model to be used in this book.

32. Example Networks The Internet
Connection-Oriented Networks: X.25, Frame Relay, and ATM
Ethernet
Wireless LANs: 802:11

33. The original ARPANET design.
The ARPANET (2)
The original ARPANET design.

34. The ARPANET (3)
Growth of the ARPANET (a) December (b) July 1970.
(c) March (d) April (e) September 1972.

35. NSFNET
The NSFNET backbone in 1988.

36. Architecture of the Internet
Overview of the Internet.

37. Architecture of the original Ethernet.

38. Wireless LANs (a) Wireless networking with a base station.
(b) Ad hoc networking.

39. The range of a single radio may not cover the entire system.
Wireless LANs (2)
The range of a single radio may not cover the entire system.

40. Wireless LANs (3)
A multicell network.

41. The principal metric prefixes.
Metric Units
The principal metric prefixes.