1
Introduction
Uses Chapter of Computer Networks
Business Applications Home Applications Mobile Users Social Issues
Business Applications of Networks
A network with two clients and one server.
Business Applications of Networks (2)
The client-server model involves requests and replies.
Home Network Applications
Access to remote information Person-to-person communication Interactive entertainment Electronic commerce
Home Network Applications (2)
In peer-to-peer system there are no fixed clients and servers.
Home Network Applications (3)
Some forms of e-commerce.
Mobile Network Users
Combinations of wireless networks and mobile computing.
Network Hardware
Local Area Networks Metropolitan Area Networks Wide Area Networks Wireless Networks Home Networks Internetworks
Broadcast Networks
Types of transmission technology Broadcast links Point-to-point links
Broadcast Networks (2)
Classification of interconnected processors by scale.
Local Area Networks
Two broadcast networks (a) Bus (b) Ring
Metropolitan Area Networks
A metropolitan area network based on cable TV.
Wide Area Networks
Relation between hosts on LANs and the subnet.
Wide Area Networks (2)
A stream of packets from sender to receiver.
Wireless Networks
Categories of wireless networks: System interconnection Wireless LANs Wireless WANs
Wireless Networks (2)
(a) Bluetooth configuration (b) Wireless LAN
Wireless Networks (3)
(a) Individual mobile computers (b) A flying LAN
Home Network Categories
Computers (desktop PC, PDA, shared peripherals Entertainment (TV, DVD, VCR, camera, stereo, MP3) Telecomm (telephone, cell phone, intercom, fax) Appliances (microwave, fridge, clock, furnace, airco) Telemetry (utility meter, burglar alarm, babycam).
Network Software
Protocol Hierarchies Design Issues for the Layers Connection-Oriented and Connectionless Services Service Primitives The Relationship of Services to Protocols
Network Software
Protocol Hierarchies
Layers, protocols, and interfaces.
Protocol Hierarchies (2)
The philosopher-translator-secretary architecture.
Protocol Hierarchies (3)
Example information flow supporting virtual communication in layer 5.
Design Issues for the Layers
Addressing Error Control Flow Control Multiplexing Routing
Connection-Oriented and Connectionless Services
Six different types of service.
Service Primitives
Five service primitives for implementing a simple connectionoriented service.
Service Primitives (2)
Packets sent in a simple client-server interaction on a connection-oriented network.
Services to Protocols Relationship
The relationship a between service and a protocol.
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
Reference Models
The OSI reference model.
Reference Models (2)
The TCP/IP reference model.
Reference Models (3)
Protocols and networks in the TCP/IP model initially.
Comparing OSI and TCP/IP Models
Concepts central to the OSI model Services Interfaces Protocols
A Critique of the OSI Model and Protocols
Why OSI did not take over the world Bad timing Bad technology Bad implementations Bad politics
Bad Timing
The apocalypse of the two elephants.
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
Hybrid Model
The hybrid reference model to be used in this book.
Example Networks
The Internet Connection-Oriented Networks: X.25, Frame Relay, and ATM Ethernet Wireless LANs: 802:11
The ARPANET
(a) Structure of the telephone system. (b) Baran's proposed distributed switching system.
The ARPANET (2)
The original ARPANET design.
The ARPANET (3)
Growth of the ARPANET (a) December 1969. (b) July 1970. (c) March 1971. (d) April 1972. (e) September 1972.
NSFNET
The NSFNET backbone in 1988.
Internet Usage
Traditional applications (1970 1990) E-mail News Remote login File transfer
Architecture of the I...