Aleksandra Smiljanic [e-mail]

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Aleksandra Smiljanicaleks_at_ece.sunysb.edu

• Local and Wide Area Networks

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Course Outline First Third
Introduction to networking Transmission
media Air, twisted pairs, coaxial cables,
optical fibers Data link techniques Error
detection and correction codes
Sliding window protocol HDLC, PPP Medium
access protocols Ethernet, FDDI, RPR
DOCSIS Wireless LAN
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Course Outline Second Third
Switches and QoS Circuit switches Clos
structure Packet switch architectures
Weighted fair queueing (WFQ), random early
detection (RED) High-capacity packet
switches Bridging Learning bridges
Spanning tree algorithm
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Course Outline Third Third
Routing Connection-oriented and
connectionless networks Distance vector
routing Link state routing OSPF, RIP
Transport end-to-end protocols TCP,
UDP Applications FTP, Telnet, Email, DNS,
WWW, Multimedia Network Security
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Introduction to Networking
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Uses of Computer Networks

• Business Applications
• Home Applications

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Business Applications

• Sharing resources
• Common databases for customer records, inventory,
  accounts
• E-commerce
• Video-conferencing
• Disseminating the information, and coordination

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Home Applications

• Getting the remote information
• Person-to-person information
• E-commerce
• Entertainment
• E-flea

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Application Types

• Some forms of e-commerce.

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Client-Server Communication

• A network with two clients and one server.

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Client-Server Communication

• The client-server model involves requests and
  replies.

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Peer-to-Peer Communication

• In peer-to-peer system there are no fixed
  clients and servers.

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Mobile and Wireless Applications

• Combinations of wireless networks and mobile
  computing.

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Wireless Applications

• Portable offices
• Trucks, taxis, police need to communicate
• Help with orientation in the area
• Car rental return
• M-commerce
• Status of the machines

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Network Types

• Local Area Networks
• Metropolitan Area Networks
• Wide Area Networks
• Wireless Networks
• Home Networks
• Internetworks

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Network Types

• Classification of interconnected processors by
  scale.

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Local Area Networks

• Two LANs
• (a) Bus-broadcast
• (b) Ring

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Metropoliten Area Networks
Switch

• Two MANs
• (a) Star-switched
• (b) Ring

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Metropolitan Area Networks

• A metropolitan area network based on cable TV.

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Wide Area Networks
Circuit switch

• Relation between hosts on LANs and the subnet.

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Wide Area Networks

• A stream of packets from sender to receiver.

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Wireless Networks

• Categories of wireless networks
• System interconnection
• Wireless LANs
• Wireless WANs

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Wireless Networks

• (a) Bluetooth configuration
• (b) Wireless LAN

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Wireless Networks

• (a) Individual mobile computers
• (b) A flying LAN

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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).

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Network Hardware

• Transmission medium
• Transceivers transmitters and receivers on the
  point-to-point connections
• Multiplexers, demultiplexers
• Packet and circuit switches
• Bridges
• Routers
• Servers, gateways, management units

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Transmission Medium

• Air different frequency bands
• Wires twisted pairs
• Coaxial cables
• Optical fibers

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Transceivers

• Transmitters perform modulation and coding to
  provide efficient and reliable communication.
• Receivers perform the reverse operations.
• Depending on the medium transceivers are
  electronic devices, antenas, or lasers and
  photodiodes.

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Multiplexers and Demultiplexers

• Multiplexers receive multiple lower bit-rate
  streams of data and according to some rule
  transmit the higher bit-rate stream of data.
• Demultiplexers do the opposite.

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Circuit and Packet Switches

• It does not make sense to connect every user with
  every other user in the network.
• Circuit and packet switches connect multiple
  inputs to multiple outputs.
• In circuit switches, the configuration pattern
  changes on a slow time scale.
• In packet switches, the configuration changes on
  a packet-per-packet basis.

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Servers, Gateways, etc.

• Servers store various kinds of information for
  users, for example DNS databases, e-mails, web
  pages and provide it to the users.
• Gateways convert data format, and negotiate QoS
  with the network.

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Network Software

• Protocol Hierarchies
• Design Issues for the Layers
• Connection-Oriented and Connectionless Services
• Service Primitives
• The Relationship of Services to Protocols

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Network SoftwareProtocol Hierarchies

• Layers, protocols, and interfaces.

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Protocol Hierarchies (2)

• The philosopher-translator-secretary architecture.

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Protocol Hierarchies (3)

• Example information flow supporting virtual
  communication in layer 5.

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Design Issues for the Layers

• Addressing
• Error Control
• Flow Control
• Multiplexing
• Routing

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Connection-Oriented and Connectionless Services

• Six different types of service.

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Service Primitives

• Five service primitives for implementing a simple
  connection-oriented service.

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Service Primitives (2)

• Packets sent in a simple client-server
  interaction on a connection-oriented network.

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Services to Protocols Relationship

• The relationship between a service and a protocol.

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Reference Models with Layers

• A layer should have well defined function
• Function of a layer should be internatinationally
  standardized
• The information flow between interfaces should be
  minimized

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Reference Models

• The OSI reference model
• The TCP/IP reference model
• Hybrid reference model

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Reference Models
The OSI reference model.
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Reference Models (2)

• The TCP/IP reference model.

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Reference Models (3)

• Protocols and networks in the TCP/IP model
  initially.

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Comparing OSI and TCP/IP Models

• Concepts central to the OSI model
• Services
• Interfaces
• Protocols
• Concept of TCP/IP
• Implementation of the required functionality with
  three layers

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A Critique of the OSI Model and Protocols

• Why OSI did not take over the world
• Bad timing
• Bad technology
• Bad implementations
• Bad politics

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Bad Timing

• The apocalypse of the two elephants.

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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

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Hybrid Model

• The hybrid reference model to be used in this
  book.

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Example Networks

• The Internet
• Connection-Oriented Networks X.25, Frame
  Relay, and ATM
• Ethernet
• Wireless LANs 802.11

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The ARPANET

• (a) Structure of the telephone system.
• (b) Barans proposed distributed switching system.

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The ARPANET

• The original ARPANET design.

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The ARPANET

• Growth of the ARPANET (a) December 1969. (b)
  July 1970.
• (c) March 1971. (d) April 1972. (e)
  September 1972.

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TCP/IP Development

• In 1974, TCP/IP model has been established by
  Cerf and Kahn, and incorporated into Berkeley
  UNIX.
• Because of the large number of hosts, domain name
  system (DNS) was created in 1980s.

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NSFNET

• The NSFNET backbone in 1988.

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Internet Usage

• Traditional applications (1970 1990)
• E-mail
• News
• Remote login
• File transfer
• World Wide Web developed by CERN physicist Tim
  Bernars-Lee, and Mark Andressen at National
  Center for Supercomputer applications

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Architecture of the Internet

• Overview of the Internet.

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ATM Virtual Circuits

• A virtual circuit.

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ATM Cell

• An ATM cell.

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The ATM Reference Model

• The ATM reference model.

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The ATM Reference Model (2)

• The ATM layers and sublayers and their functions.

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Ethernet

• Architecture of the original Ethernet.

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Wireless LANs

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

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Wireless LANs

• The range of a single radio may not cover the
  entire system.

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Wireless LANs

• A multicell 802.11 network.

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Network Standardization

• Whos Who in the Telecommunications World
• Whos Who in the International Standards World
• Whos Who in the Internet Standards World

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WLAN Issues

• CSMA/CD may not be applicable
• Multipath fading
• Mobility

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ITU

• Main sectors
• Radiocommunications
• Telecommunications Standardization
• Development
• Classes of Members
• National governments
• Sector members (ATT, Cisco, Intel, AOL Time
  Warner)
• Associate members
• Regulatory agencies (FCC)

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ISO

• 200 Technical Committees, divided into
  subcommittees, and working groups involving
  100000 voluneers.
• TC97 in charge for computers and information
  processing.
• American National Standards Institute (ANSI) is
  US representative in ISO.
• National standards organization -gt committee
  draft -gtdraft international standard -gt standard

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IEEE 802 Standards
The 802 working groups. The important ones are
marked with . The ones marked with ? are
hibernating. The one marked with gave up.
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Internet Standards

• In 1983, Internet Activities Board (IAB) was
  established.
• Communication was done through request for
  comments (RFC) documents.
• IAB is moved to Internet Research Task Force
  (IRTF) and Internet Engineering Task Force.
• Proposed standard -gt draft standard -gt standard