������������ ������������ ��������������� ��������������������� 2004/2005 ������� ���������������������������� ���������������� ��������������������������������������� ������������� �������������������������� ������ ����������������������� ������ �� ������� ���������!��� �� G. Bianchi, G. Neglia ����������� ����������� �������� �������� �� �� ��������� ����������������� �������� 1. transmission technologies � physical carriers, modulation, etc 2. data link protocols � reliable transfer of bits from point to point 3. Packet switching � Historical perspective, then technologies, routing, protocols, finally IP 4. Packet forwarding � Glue IP routing with layer 2, ARP,... 5. Transport protocols, application protocols � In a rush!! (just a bit of TCP, HTTP, …) G. Bianchi, G. Neglia �������� ������� �������� ������� ��� ������� ���� ������ ������ � (almost) Top-Down � Applications are indeed important � What you see is what you learn first � Start focusing on internet application programming � Notion and usage of sockets (JAVA examples) � Transport layer as application developement platform � Web as driving application � Limited details on other apps G. Bianchi, G. Neglia 1
Course Course objectives objectives & limits & limits � ������� �!" � "��������������������������������#�����$������������������ � "������������ ��� ����� ��� ���� ���� �������� �� ���� ��� � � ������� ��������� �� ������� �� ������ %�������� ���� ��&�'�������� � #������ ���� �� ����(����� �� � �������� ����� � #�$��!" � � ����������� �� )*���+�������������#���,����������#��� %��� ������� �� ����-������� ������������������ �� . ����������� ���������� ������&� � /�������������� � ����� �� $��������%���������� �� �� ��� �������������& G. Bianchi, G. Neglia Teaching Material Material Teaching � Book and notes � Nicola Blefari Melazzi, dispense, versione 4.2 (in italian), 2003 � Available online � In progress (310 pages at the moment) � James F. Kurose, Keith W. Ross, 2000 � Italian version: Internet e reti di calcolatori, McGraw-Hill, approx 40 � � top-down approach � Additional reference books & material � Stevens (vol. 1), 1994 � to dip into technical issues � a VALUABLE book (though a bit too old) � RFCs: the real stuff… � Sites: � www.ietf.org � Internet standardization � www.w3.org � Web standardization G. Bianchi, G. Neglia Course contents Course contents � PART A: Applications � Internet architecture, internet standardization, switching basics � Application addressing, Internet applications development (JAVA-based) � World wide web; HTTPv1.0 details � Domain Name System � PART B: Transport � User Datagram Protocol � Introduction to TCP, pipelining, performance issues � TCP algorithms: (a) window flow control; (b) TCP error control; (c) TCP congestion control. � PART C: Network � IP addressing � IP packet forwarding (ARP), IP address assignment (RARP, DHCP) � Advanced IP addressing: subnetting & supernetting (CIDR) � IP and ICMP details � IP routing � extra Time? Never happened… G. Bianchi, G. Neglia 2
Internet Internet traffic traffic growth growth (USA - - recent recent measurements measurements) ) (USA G. Bianchi, G. Neglia Traffic share share - - projections projections Traffic IP TRAFFIC MIX - P2P SCENARIO 100% SHARE OF TOTAL TRAFFIC 90% 80% 70% WEB PAGES 60% RICH MEDIA 50% P2P 40% S2S 30% 20% 10% 0% 2001 2002 2003 2004 2005 2006 2007 2008 source: Cohen Communications Group G. Bianchi, G. Neglia Why Why “ “All All” over IP? ” over IP? Packet 15 Times 1200 Greater Than Circuit PetaBytes per Month 1000 800 Telephony 600 Internet 400 200 0 97 98 99 00 01 02 Year End Source: M. Decina, 2000 G. Bianchi, G. Neglia 3
Voice over IP Voice over IP – – deployment deployment (source: F. Carlini, november 2003) (source: F. Carlini, november 2003) � ITA: Fastweb � All-IP Voice service � ITA: Telecom Italia � 100% (!!) Telephone traffic, MI-RM-NA backbone is IP � Did you know? � International traffic � 12% of whole international traffic is IP � Ongoing direction: � User VoIP awareness (e.g. Fastweb) G. Bianchi, G. Neglia What was was the Internet the Internet What ( for ) ( ago ) for the mass the mass- -media, a few media, a few years years ago � Internet synonimous of WWW ( W orld W ide W eb) sites & pages: � millions of documents � Spreaded worldwide � mostly written in HTML language ( HyperText Markup Language ) � mostly accessible via the HTTP protocol ( HyperText Transfer Protocol ) G. Bianchi, G. Neglia What was was the Internet the Internet What ( for ( in the 80s ) ) for the the scientist scientist in the 80s � Internet synonimous of FTP ( F ile T ransfer P rotocol) and e-mail: � Scientists were the only ones having a presence on the Internet (unix logins) » contacts via email, talk program � Research documents archived in FTP sites » accessible via FTP, gopher � Scientific (and cultural) forums: Usenet news G. Bianchi, G. Neglia 4
What What is is the internet the internet ( for ) ( for the mass media, the mass media, today today ) � Huge marketplace for e-business � B2B and B2C portals with full-fledged transaction capabilities � Virtual communities � Chat & messaging � Peer to peer applications � Communication network � IP Telephony / Multimedia commun. G. Bianchi, G. Neglia What will will be be the Internet the Internet What (in 2010?) (in 2010?) � High speed unique integrated telecommunication network and business services platform � High Speed = Broadband � Unique = integrated services network � Services = from communication to distributed systems � ??? � Worldwide operating system? � Content delivery network? p2p? ??? � Internet Appliances, the real revolution? ??? G. Bianchi, G. Neglia What What is is the Internet the Internet (For For networking networking engineers engineers: : We We!) !) ( 1. A worldwide computer network � Connecting end-systems (host, servers) � Each uniquely identified by a numeric address (IP address) 2. the world wide group of networks combined with TCP/IP � TCP/IP synonimous of the entire suite of networking protocols. � The name comes from the two most important: » TCP = Transmission Control Protocol » IP = Internet Protocol 3. A packet switching network G. Bianchi, G. Neglia 5
TCP/IP characteristics TCP/IP characteristics � TCP/IP provides services necessary to create the Internet, by: � interconnecting computers & � interconnecting networks � Independence from underlying network topology, physical network hardware, Operating Systems, etc � Universal connectivity throughout the network � Standardize High Level protocols G. Bianchi, G. Neglia What Internet What Internet is is: a network of : a network of heterogeneous networks networks heterogeneous Internet and host Private Nets Token router %�&�� ����� router Power- &��'&��� Ring line central !�������� ���' Power Ethernet line Host = 1 interface Router = 2+ interfaces G. Bianchi, G. Neglia What Internet What Internet attempts attempts to to be be ( (but but only only loosely loosely is is): ): a hierarchical hierarchical network... network... a G. Bianchi, G. Neglia 6
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