introduction chapter 1 [email protected]. uses of computer networks business applicationsbusiness...
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Uses of Computer NetworksUses of Computer Networks
• Business ApplicationsBusiness Applications
• Home ApplicationsHome Applications
• Mobile UsersMobile Users
• Social IssuesSocial Issues
Business Applications of NetworksBusiness Applications of Networks
A network with two clients A network with two clients and one server.and one server.
Business Applications of Networks (2)Business Applications of Networks (2)
The client-server model involves The client-server model involves requests and replies.requests and replies.
Home Network ApplicationsHome Network Applications
• Access to remote informationAccess to remote information
• Person-to-person communicationPerson-to-person communication
• Interactive entertainmentInteractive entertainment
• Electronic commerceElectronic commerce
Home Network Applications (2)Home Network Applications (2)
In peer-to-peer system there are no fixed In peer-to-peer system there are no fixed clients and servers.clients and servers.
Mobile Network UsersMobile Network Users
Combinations of wireless networks and Combinations of wireless networks and mobile computing.mobile [email protected]
Network HardwareNetwork Hardware
• Local Area NetworksLocal Area Networks
• Metropolitan Area NetworksMetropolitan Area Networks
• Wide Area NetworksWide Area Networks
• Wireless NetworksWireless Networks
• Home NetworksHome Networks
• InternetworksInternetworks
Broadcast NetworksBroadcast Networks
Types of transmission technologyTypes of transmission technology
• Broadcast linksBroadcast links
• Point-to-point linksPoint-to-point links
Broadcast Networks (2)Broadcast Networks (2)
Classification of interconnected Classification of interconnected processors by scale.processors by [email protected]
Local Area NetworksLocal Area Networks
Two broadcast Two broadcast networksnetworks(a)(a) Bus Bus(b)(b) Ring Ring
Metropolitan Area NetworksMetropolitan Area Networks
A metropolitan area network based A metropolitan area network based on cable TV.on cable [email protected]
Wide Area NetworksWide Area Networks
Relation between hosts on LANs Relation between hosts on LANs and the subnet.and the [email protected]
Wide Area Networks (2)Wide Area Networks (2)
A stream of packets from sender A stream of packets from sender to receiver.to [email protected]
Wireless NetworksWireless Networks
Categories of wireless networks:Categories of wireless networks:
• System interconnectionSystem interconnection
• Wireless LANsWireless LANs
• Wireless WANsWireless WANs
Wireless Networks (2)Wireless Networks (2)
(a)(a) Bluetooth configuration Bluetooth configuration(b)(b) Wireless LAN Wireless LAN
Wireless Networks (3)Wireless Networks (3)
(a)(a) Individual mobile Individual mobile computerscomputers(b)(b) A flying LAN A flying LAN
Home Network CategoriesHome Network Categories
• Computers (desktop PC, PDA, shared peripheralsComputers (desktop PC, PDA, shared peripherals• Entertainment (TV, DVD, VCR, camera, stereo, MP3)Entertainment (TV, DVD, VCR, camera, stereo, MP3)• Telecomm (telephone, cell phone, intercom, fax)Telecomm (telephone, cell phone, intercom, fax)• Appliances (microwave, fridge, clock, furnace, airco)Appliances (microwave, fridge, clock, furnace, airco)• Telemetry (utility meter, burglar alarm, babycam).Telemetry (utility meter, burglar alarm, babycam).
Network SoftwareNetwork Software
• Protocol HierarchiesProtocol Hierarchies• Design Issues for the LayersDesign Issues for the Layers• Connection-Oriented and Connectionless ServicesConnection-Oriented and Connectionless Services• Service PrimitivesService Primitives• The Relationship of Services to ProtocolsThe Relationship of Services to Protocols
Network SoftwareNetwork SoftwareProtocol HierarchiesProtocol Hierarchies
Layers, protocols, and Layers, protocols, and [email protected]
Protocol Hierarchies (2)Protocol Hierarchies (2)
The philosopher-translator-secretary The philosopher-translator-secretary [email protected]
Protocol Hierarchies (3)Protocol Hierarchies (3)
Example information flow supporting virtual Example information flow supporting virtual communicationcommunication in layer 5. in layer [email protected]
Design Issues for the LayersDesign Issues for the Layers
• AddressingAddressing• Error ControlError Control• Flow ControlFlow Control• MultiplexingMultiplexing• RoutingRouting
Connection-Oriented and Connectionless Connection-Oriented and Connectionless ServicesServices
Six different types of Six different types of service.service.
Service PrimitivesService Primitives
Five service primitives for implementing Five service primitives for implementing a simple a simple connection-connection-oriented service.oriented service.
Service Primitives (2)Service Primitives (2)
Packets sent in a simple Packets sent in a simple client-server interaction client-server interaction on a on a connection-oriented connection-oriented network.network.
Services to Protocols RelationshipServices to Protocols Relationship
The relationship between a service The relationship between a service and a protocol.and a protocol.
Reference ModelsReference Models
• The OSI Reference ModelThe OSI Reference Model
• The TCP/IP Reference ModelThe TCP/IP Reference Model
• A Comparison of OSI and TCP/IP A Comparison of OSI and TCP/IP
• A Critique of the OSI Model and ProtocolsA Critique of the OSI Model and Protocols
• A Critique of the TCP/IP Reference ModelA Critique of the TCP/IP Reference Model
Reference Models (2)Reference Models (2)
The TCP/IP reference The TCP/IP reference [email protected]
Reference Models (3)Reference Models (3)
Protocols and networks in the Protocols and networks in the TCP/IP model initially.TCP/IP model [email protected]
Comparing OSI and TCP/IP ModelsComparing OSI and TCP/IP Models
Concepts central to the OSI modelConcepts central to the OSI model
• ServicesServices
• InterfacesInterfaces
• ProtocolsProtocols
A Critique of the OSI Model and ProtocolsA Critique of the OSI Model and Protocols
Why OSI did not take over the worldWhy OSI did not take over the world
• Bad timingBad timing
• Bad technologyBad technology
• Bad implementationsBad implementations
• Bad politicsBad politics
Bad TimingBad Timing
The apocalypse of the The apocalypse of the two elephants.two elephants.
A Critique of the TCP/IP Reference ModelA Critique of the TCP/IP Reference Model
Problems:Problems:• Service, interface, and protocol not distinguishedService, interface, and protocol not distinguished• Not a general modelNot a general model• Host-to-network “layer” not really a layerHost-to-network “layer” not really a layer• No mention of physical and data link layersNo mention of physical and data link layers• Minor protocols deeply entrenched, hard to replaceMinor protocols deeply entrenched, hard to replace
Hybrid ModelHybrid Model
The hybrid reference model to be used in this book.The hybrid reference model to be used in this book.
Example NetworksExample Networks
• The InternetThe Internet
• Connection-Oriented Networks:Connection-Oriented Networks: X.25, Frame Relay, and ATM X.25, Frame Relay, and ATM
• EthernetEthernet
• Wireless LANs: 802:11Wireless LANs: 802:11
The ARPANETThe ARPANET
(a)(a) Structure of the telephone Structure of the telephone system.system.(b)(b) Baran’s proposed distributed Baran’s proposed distributed switching system.switching system.
The ARPANET (3)The ARPANET (3)
Growth of the ARPANET Growth of the ARPANET (a)(a) December 1969December 1969. . (b)(b) July 1970July 1970..(c)(c) March 1971. March 1971. (d)(d) April 1972. April 1972. (e) September 1972(e) September 1972. .
Internet UsageInternet Usage
Traditional applications (1970 – 1990) Traditional applications (1970 – 1990)
• E-mailE-mail
• NewsNews
• Remote loginRemote login
• File transferFile transfer
Architecture of the InternetArchitecture of the Internet
Overview of the Overview of the [email protected]
The ATM Reference ModelThe ATM Reference Model
The ATM reference The ATM reference [email protected]
The ATM Reference Model (2)The ATM Reference Model (2)
The ATM layers and sublayers and The ATM layers and sublayers and their functions.their [email protected]
EthernetEthernet
Architecture of the Architecture of the original Ethernet.original Ethernet.
Wireless LANsWireless LANs
(a)(a) Wireless networking with a base Wireless networking with a base station.station.(b)(b) Ad hoc networking. Ad hoc networking.
Wireless LANs (2)Wireless LANs (2)
The range of a single radio may not The range of a single radio may not cover the entire system.cover the entire [email protected]
Network StandardizationNetwork Standardization
• Who’s Who in the Telecommunications WorldWho’s Who in the Telecommunications World• Who’s Who in the International Standards WorldWho’s Who in the International Standards World• Who’s Who in the Internet Standards WorldWho’s Who in the Internet Standards World
ITUITU
• Main sectorsMain sectors• RadiocommunicationsRadiocommunications• Telecommunications StandardizationTelecommunications Standardization• DevelopmentDevelopment
• Classes of MembersClasses of Members• National governmentsNational governments• Sector membersSector members• Associate membersAssociate members• Regulatory agenciesRegulatory agencies
IEEE 802 StandardsIEEE 802 Standards
The 802 working groups. The important The 802 working groups. The important ones are marked with *ones are marked with *. The . The ones marked with ones marked with are hibernating are hibernating. The one marked with †. The one marked with † gave up. gave up.
Metric UnitsMetric Units
The principal metric The principal metric prefixes.prefixes.