Politecnico di Milano Scuola di Ingegneria Industriale e dell’Informazione

Fundamentals of Communication Networks

Prof. Antonio Capone

Teacher o  Prof. Antonio Capone o  Office:

n  Dip. di Elettronica, Informazione e Bioingegneria - DEIB

n  3° piano n  stanza 335

o  Tel: (02 2399) 3449 o  E-mail: antonio.capone@polimi.it o  Web page:

n  http://home.deib.polimi.it/capone/ o  Office hours:

n  Martedì 14.00-15.30

Exams

o Written and oral exam n  4 Numerical exercises n  1 Set of questions n  Oral exam if written score >=15

Teaching material (1)

o Reference books: n  A. S. Tanenbaum, D. J. Wetherall,

“Computer Networks”, Fifth Edition, Pearson n  James F. Kurose, Keith W. Ross, “Computer

Networking: a top down approach”, Editore: Pearson

Teaching material (2)

o Other books n  Saadawi Tarek N. , Ammar Mostafa H.,

El Hakeem Ahmed, “Fundamentals of telecommunication networks” Wiley

n  Fred Halsall, “Data Communications, Computer Networks, and Open Systems” Addison-Wesley

n  Behrouz A. Forouzan, TCP/IP protocol suite, McGraw-Hill

n  Douglas E. Comer, Internetworking with TCP/IP, Addison-Wesley

Teaching material (3)

o  Lecture slides o Other material and links o Course web site

Course home page

Course objetive

o  Provide you the basics of computer networks

o  Present you the “building blocks” of the Internet

This basic knowledge is fundamental for the advanced topics covered by most of the other courses of the MSc program

Background

Software applications exchange information with remote applications

For communicating they use: The INTERNET

Communications uses physical media and are subject to rules (protocols) o We will deal with:

n  How to support communications n  Protocols used at different layers n  Network infrastructures

Probability Theory

o  In addition to Communication Networks, the course provides also the basics of probability theory

o  This is instrumental to some advanced course of networking like Traffic Theory, but also to other courses of the study program

Course program

o Basics of probability theory n  Probabilities

o  Definitions o  Uniform spaces o  Conditional spaces o  Bayes’ Formulas o  Statistical independence

n  Random Variables o  Spaces with infinite outcomes o  Continuous Random Variables o  Discrete Random Variables o  Moments of a pdf o  Conditional distributions and densities o  Vectorial Random Variables o  Functions of Random Variables

Course program

o  Functional models n  Protocols n  Communication services n  Stack models and main functions

o  Physical layer n  Multiplexing n  Multiple access n  Transport networks

o  Link layer n  Framing n  Error control n  Retransmission n  Flow control n  Link protocol example (HDLC)

Course program

o  Local Area Networks n  Random access n  Ethernet n  Bridging

o  Internet architecture o  Network layer: IP

n  Addressing n  Forwarding and routing n  Control protocols n  Routing protocols

Course program o  Transport layer

n  UDP n  TCP

o  Application layer n  Name management: DNS n  File transfer: FTP n  Web Browsing: HTTP n  E-mail: (SMTP) n  Peer-To-Peer applications

o  Private networks n  Private addressing n  Tunnels n  NAT

o  MPLS o  IPv6

Politecnico di Milano Scuola di Ingegneria Industriale e dell’Informazione

Introduction

Fundamentals of Communication Networks

A bit of history

The born of the Internet: 60s

o  1961: Kleinrock – shows the effectiveness of packet switching with queuing theory

o  1967: Lawrence Roberts designs ARPAnet (Advanced Research Projects Agency)

o  1969: first network node IMP (Interface Message Processor) di ARPAnet at UCLA

The born of the Internet: 70s o  1972:

n  NCP (Network Control Protocol) the first Internet protocol

n  First email application n  ARPAnet has 15 nodes

o  1970: n  ALOHAnet radio packet

network at Univ. of Hawaii

o  1974: n  Cerf and Kahn – design

internetworking (network of networks) principles

o  1976: n  Ethernet is designed in

the Xerox labs o  1979:

n  ARPAnet has 200 nodes

The born of the Internet: 80s

o  1982: SMTP for email is defined

o  1983: TCP/IP suite replaces NCP

o  1983: DNS is defined for mapping of names and addresses

o  1985: FTP protocol o  1988: congestion

control of TCP

o  New national networks: Csnet, BITnet, NSFnet, Minitel

o  100.000 hosts

First applications

o  Telnet o  Email

o  FTP

The born of the Internet: 90s o  1990: ARPAnet is

discontinued o  1991: NSF allows

commercial use of NSFnet

o  First 90s: Tim Berners-Lee invents the web at Cern in Genève

o  1994: First browser Mosaic, then Netscape

o  End of 90s: explosion of commercial use of the Web

The born of the Internet: 2000s

2000s: o  New “killer

applications”: instant messaging, P2P file sharing, IP Telephony, social networks

o  Network security o  Billions of users o  Link speeds up to

few Gbps Zuckerberg

Diffie-Hellman-Merkle

Shawn Fanning

The born of the Internet: 10s

10s - today: o  Mobile internet o  iPhone o  Android o  Application markets

http://www.caida.org

24

World is small

Internet growth

Jul 2013 996,230,757

Internet vs mobile networks

Per 100 inhabitants o  96 mobile subscribers o  16 fixed lines o  39 internet users o  10 fixed-broadband o  29 mobile-broadband

Source: ITU Data: 2012