【正文】 計算機網(wǎng)絡技術的 歷史和新進展 主要內(nèi)容 ? Inter的發(fā)展和成功經(jīng)驗 ? 高速計算機網(wǎng)絡技術發(fā)展的現(xiàn)狀 ? 國際高速計算機網(wǎng)絡技術研究計劃 ? 中國計算機網(wǎng)絡技術研究計劃 ? 高速計算機網(wǎng)絡技術發(fā)展戰(zhàn)略 ? 機會和挑戰(zhàn)并存，挑戰(zhàn)大于機會 What is a Network? (from end system point of view) ? Network offers a service: move information – bird, fire, messenger, truck, telegraph, telephone, Inter … – another example, transportation service: move objects ? horse, train, truck, airplane ... ? What distinguish different types of works? – The services they provide ? What distinguish the services? – latency – bandwidth – loss rate – number of end systems – service interface (how to invoke?) – other details ? reliability, unicast vs. multicast, realtime, message vs. byte ... What is a Network? Infrastructure Centric View ? Electrons and photons as munication medium ? Links: fiber, copper, satellite, … ? Switches: mechanical/electronic/optical, crossbar/Banyan ? Protocols: TCP/IP, ATM, MPLS, SONET, Ether, PPP, , FrameRelay, AppleTalk, IPX, SNA ? Functionalities: routing, error control, congestion control, Quality of Service (QoS) ? Applications: FTP, WEB, X windows, ... Types of Networks ? Geographical distance – Local Area Networks (LAN): Ether, Token ring, FDDI – Metropolitan Area Networks (MAN): DQDB, SMDS – Wide Area Networks (WAN): , ATM, frame relay ? Information type – data works vs. telemunication works ? Application type – special purpose works: airline reservation work, banking work, credit card work, telephony – general purpose work: Inter Types of Networks ? Right to use – private: enterprise works – public: telephony work, Inter ? Ownership of protocols – proprietary: SNA – open: IP ? Technologies – terrestrial vs. satellite – wired vs. wireless ? Protocols – IP, AppleTalk, SNA The Inter ? Global scale, general purpose, heterogeneoustechnologies, public, puter work ? Inter Protocol – open standard: Inter Engineering Task Force (IETF) as standard body – technical basis for other types of works ? Intra: enterprise IP work ? Developed by the research munity History of the Inter ? 70’ s: started as a research project, 56 kbps, 100 puters ? 8083: ARPANET and MILNET split, ? 8586: NSF builds NSFNET as backbone, links 6 Superputer centers, Mbps, 10,000 puters ? 8790: link regional works, NSI (NASA), ESNet(DOE), Bart, 100,000 puters ? 9092: NSFNET moves to 45 Mbps, 16 midlevel works ? 94: NSF backbone dismantled, multiple private backbones ? Today: backbones run at Gbps, 10s millions puters in 150 countries Growth of the Inter ? Number of Hosts on the Inter: Aug. 1981 213 Oct. 1984 1,024 Dec. 1987 28,174 Oct. 1990 313,000 Oct. 1993 2,056,000 Apr. 1995 5,706,000 Jul. 1997 19,540,000 Jul. 2023 93,047,785 1101001000100001000001000000100000001000000001981年 1986年 1991年 1996年 Recent Growth (19912023) Who is Who on the Inter ? ? Inter Engineering Task Force (IETF): The IETF is the protocol engineering and development arm of the Inter. Subdivided into many working groups, which specify Request For Comments or RFCs. ? IRTF (Inter Research Task Force): The Inter Research Task Force is a posed of a number of focused, longterm and small Research Groups. ? Inter Architecture Board (IAB): The IAB is responsible for defining the overall architecture of the Inter, providing guidance and broad direction to the IETF. ? The Inter Engineering Steering Group (IESG): The IESG is responsible for technical management of IETF activities and the Inter standards process. Standards. Composed of the Area Directors of the IETF working groups. Inter Standardization Process Services Provided by the Inter Today’ s Vision ? Everything is digital: voice, video, music, pictures, live events ? Everything is online: bank statement, medical record, books, airline