EECS 3213 Fall 2014 L2: Introduction to Communication Networks: Internet Sebastian Magierowski York University EECS 3213, F14 L2: Intro Internet 1 Outline • ARPANET – A connectionless datagram network • Internet – A connectionless/connection-oriented datagram network – best-effort service • Local Area Networks – Ethernet: connectionless protocol, medium access control EECS 3213, F14 L2: Intro Internet 2 1 Internet • An internetwork • Multi-tiered, decentralized organization • A network of computers – Powerful processing at network edge – Move communication complexity towards the edge – Develop sophisticated protocols SEC. 1.5 EXAMPLE NETWORKS 55 EECS 3213, F14 SEC. 1.5L2: Intro EXAMPLEInternet NETWORKS 55 3 Of course, countless technical books have been written about the Internet and its protocols as well. For more information,Of course, countless see, for example,technical Maufer books have (1999). been written about the Internet and its protocols as well. For more information, see, for example, Maufer (1999). The ARPANET The ARPANET The story begins in the late 1950s. At the height of the Cold War, the U.S. The story begins in the late 1950s. At the height of the Cold War, the U.S. DoD wanted a command-and-control network that could survive a nuclear war. DoD wanted a command-and-control network that could survive a nuclear war. At that time, all military communicationsAt that time, all usedmilitary the publiccommunications telephone used network, the public telephone network, which was considered vulnerable.which wasThe considered reason for vulnerable.this belief can The be reason gleaned for from this belief can be gleaned from Fig. 1-25(a). Here the blackFig. dots 1-25(a).represent Here telephone the blackswitching dots represent offices, telephoneeach of switching offices, each of which was connected to thousandswhichTelephone was of telephones.connected toThese thousands vs. switching ofInternet telephones. offices were,These switching offices were, in turn, connected to higher-levelin turn, switching connected officesto higher-level (toll offices), switching to form offices a (toll offices), to form a national hierarchy with onlynational a small hierarchy amount of withredundancy. only a small The amount vulnerability of redundancy. of The vulnerability of the system was that the destructionthe system of a was few that key the toll destruction offices could of a fragment few key toll it into offices could fragment it into Publicmany isolatedSwitched islands. Telephonemany isolated Network islands. Distributed Switching System (PSTN) Switching Switching office office Toll Toll office office • U.S. military(a) dependent (a)on PSTN(b) in 50’s (b) Figure 1-25. (a) Structure of the Figuretelephone 1-25. system.(a) Structure (b) Baran’s of the proposedtelephone dis- system. (b) Baran’s proposed dis- • Easytributed to switching cripple system. bytributed taking switching system.out switching centers Around 1960, the DoD awardedAround a contract 1960, the to theDoD RAND awarded Corporation a contract to to find the RAND a Corporation to find a • solution.RAND One ofCorp. its employees, (Paulsolution. Paul One Baran,Baran of cameits employees,) up proposes with the Paul highly Baran, distributed camea distributed up with the highly distributed network and fault-tolerant design of Fig. 1-25(b). Since the paths between any two switch- and fault-tolerant design of Fig. 1-25(b). Since the paths between any two switch- ing offices were now much longer than analog signals could travel without distor- ing offices were now much longer than analog signals could travel without distor- • AT&T rejectedtion, the Baran idea proposed when using digital askedpacket-switching to build technology. prototypeBaran wrote sev- tion, Baran proposed using digital packet-switching technology. Baran wrote sev- eral reports for the DoD describing his ideas in detail (Baran, 1964). Officials at eral reports for the DoD describing his ideas in detail (Baran, 1964). Officials at the Pentagon liked the concept and asked AT&T, then the U.S.’ national tele- EECS 3213,the Pentagon F14 liked the conceptphone and monopoly, asked AT&T,L2: to build Intro then a Internet prototype. the U.S.’ national AT&T dismissed tele- Baran’s ideas out of 4 phone monopoly, to build ahand. prototype. The biggest AT&T and dismissed richest corporation Baran’s ideas in the out world of was not about to allow hand. The biggest and richest corporation in the world was not about to allow 2 5858 INTRODUCTIONINTRODUCTION CHAP. 1 CHAP. 1 58 INTRODUCTIONARPANET CHAP. 1 nodenode by by a ateam team58 led led by Lenby58 Len Kleinrock Kleinrock (a pioneer (aINTRODUCTION pioneer of the theoryINTRODUCTION of the of theory packet of switching) packet switching)CHAP.CHAP. 1 1 node by atoto team the the SRI led SRI by node. node. Len The Kleinrock The network network (a grew pioneer grew quickly of quicklythe as theory more as of IMPs more packet were IMPs switching) delivered were delivered and and to the SRIinstalled; node. it The soonnode network spanned by a team grewnode the led Unitedby quickly by a team Len States. asled Kleinrock moreby Len Figure IMPs Kleinrock (a pioneer 1-27 were shows (a of pioneer delivered the how theory of rapidlythe and of theory packet the of packetswitching) switching) installed; itto soon the spannedSRI node.to the the SRIThe United node. network The States. grew network quickly Figure grew as quickly 1-27 more shows as IMPs more were how IMPs delivered rapidly were delivered andthe and • installed;RANDARPANET it soon idea spanned grew implemented in the the United firstinstalled; 3 years. States. it soon Figurein spanned late 1-27 the 60’s shows United States.howas rapidlynetwork Figure 1-27the shows of how rapidly the ARPANETinstalled; grew inthe it soon first spanned 3 years. the United States. Figure 1-27 shows how rapidly the ARPANET grew in the first 3 years.ARPANET grew in the first 3 years. computersSRI UTAH betweenARPANETSRI grew UTAH research inMIT the first 3 years.SRI centers UTAH ILLINOIS MIT LINCOLN CASE SRI UTAH MIT SRI UTAH ILLINOIS MIT LINCOLN CASE SRI UTAH SRI UTAH MIT SRI UTAH ILLINOIS MIT LINCOLN CASE SRI UTAH SRI UTAH MIT SRI UTAHSRI UTAH ILLINOIS MIT LINCOLN CASE SRI UTAH SRI UTAH MIT SRI UTAH ILLINOIS MIT LINCOLN CASE UCSB UCSB SDC UCSB SDC CARN UCSBSTAN SDC UCSB SDC CARN UCSBUCSB SDC UCSB SDC CARN UCSB UCSB SDC UCSB SDC STANCARN UCSB UCSB UCSB SDC UCSB SDC CARN STAN STAN UCLA UCLA RAND BBN UCLA RAND STANBBN HARVARD BURROUGHS UCLA UCLA RAND BBN UCLA RAND BBN HARVARD BURROUGHS (a) (b) (c) UCLA UCLAUCLA RANDUCLAUCLABBN RAND(a) UCLAUCLABBNRANDRANDBBN(b)UCLABBNUCLARANDHARVARDRAND BURROUGHSBBN BBNHARVARDHARVARD(c) BURROUGHS BURROUGHS Dec. (a)’69 (a) (b) (a) July(b) ’70(b) (c) Mar.(c) (c) ’71 SRI LBL MCCLELLAN SRIUTAH ILLINOISLBL MCCLELLAN MIT UTAH ILLINOIS MIT CCA CCA MCCLELLAN MCCLELLAN SRI LBL MCCLELLANAMES TIP UTAH ILLINOIS MIT AMES TIP BBN SRI LBL MCCLELLANSRI LBLUTAHMCCLELLANILLINOISUTAHBBN MIT ILLINOIS MIT SRI UTAH NCAR GWC LINCOLNSRI CASEUTAH NCAR GWC LINCOLN CASE HARVARD AMES IMP HARVARDAMES IMP LINC CCA LINC MCCLELLAN AMES TIPX-PARC ABERDEEN X-PARC RADC ABERDEENCCA BBN MCCLELLAN RADC AMES TIPILLINOIS STANFORD CCA ILLINOIS CARN NBS Apr. ’72 MCCLELLAN SRI UTAH AMES NCAR CARN GWC USC LINCOLN Sept. CASESTANFORDAMES ’72 TIP BBNNBS HARVARD AMES USC LINC AMES IMP BBNETAC LINC SRI UTAH NCAR GWC LINCOLNUCSB CASELINC X-PARCMITRE HARVARDFNWCETAC RAND SRI UTAH NCAR GWC LINCOLN CASEAMESRADC IMP MIT LINC ABERDEEN UCSB MITREILLINOIS FNWC RAND HARVARDTINKER ARPA MIT STANX-PARCSDC CARN AMESABERDEENTINKER IMP STANFORD NBS LINC AMESRADC USC ETAC ARPA STAN ILLINOISSDC LINC X-PARC ABERDEEN MITRE CARN ETACRADC STANFORD NBS ETAC RADC AMES USC UCSB ILLINOIS MITRE FNWC RANDUCSBMITRE UCSD SAAC LINC MIT ETACSTANFORD TINKER RADCNBS UCLA RANDCARNTINKERUCSBBBN UCSDHARVARD NBS ARPA UCSB AMES USC STAN MITRESDC LINCFNWC RAND SAAC BELVOIR MIT ETAC TINKER ETAC UCSBUCLA RAND TINKER BBN HARVARD NBS FNWC RAND BELVOIR MITRE RADC CMU STAN SDC MIT MITRE ARPA ETAC UCSB UCSD TINKER CMU SAAC STAN SDC MITRE RADC ARPA UCLA RAND TINKER BBNETACHARVARD NBS UCLA SDC USC BELVOIRNOAA GWC CASE UCSB UCSD SAAC MITRE UCLA (d) SDC USC NOAA GWC CASE(e) CMURADC • RetiredUCLA RAND inTINKER ‘90BBN atHARVARD >100 NBS hosts UCSB UCSD BELVOIR SAAC UCLA RAND TINKER(d) BBN HARVARD NBS UCLA (e)SDC USCCMU NOAA BELVOIRGWC CASE – California - Norway Figure(d) 1-27. Growth of the ARPANET. (a) December(e)1969. (b) JulyCMU 1970. UCLA(c) March 1971.SDC (d)USC April 1972.NOAA (e) SeptemberGWC 1972. CASE EECS 3213, F14 Figure(d) 1-27. Growth of the ARPANET.L2: Intro(a) Internet DecemberUCLA (e) 1969.SDC (b) JulyUSC 1970. NOAA GWC CASE 5 (c) March 1971. (d) April 1972. (e) September 1972. Figure(d) 1-27. Growth of the ARPANET. (a) December 1969.(e) (b) July 1970. (c) MarchIn 1971. addition (d) April to helping1972. (e) the September fledgling 1972. ARPANET grow, ARPA also funded re- Figure 1-27. Growth of the ARPANET.search on(a) the December use of satellite1969.networks (b) July 1970. and mobile packet radio networks. In one In addition to helping the fledgling ARPANET grow, ARPA also funded re- (c) March 1971.Figure (d) April 1-27. 1972.Growthnow (e) September offamous the ARPANET. demonstration, 1972. (a) December a truck driving1969. around (b) July in 1970. California used the packet search on the useIn of additionsatellite tonetworks helping and the fledglingmobile packet ARPANET radio networks. grow, ARPA In onealso funded re- (c) March 1971. (d)radio April network 1972.(e) to send September messages 1972. to SRI, which were then forwarded over the now famous demonstration,search on theARPANET use a truck of satellite drivingto thenetworks East around Coast, and in where California mobile they packet were used shipped radio the packet networks. to University In College one in In additionradio network to helpingnow to sendthe famous fledgling messagesLondon demonstration, ARPANET over to SRI,the s aatellite which truck grow,network.