How about full connections? o(n connections, where N is number of users Cost and complexity are terribly large
Communication Networks How about Full Connections? • 𝑂 𝑁 2 connections, where 𝑁 is number of users – Cost and complexity are terribly large 7
What are Networks? All the users share the same network, including a set of Nodes. Links. protocols Users can obtain a set of resources to support their communications when they need
Communication Networks What are Networks? • All the users SHARE the same network, including a set of: – Nodes, Links, Protocols • Users can obtain a set of resources to support their communications when they need 8
Outline Why need networks History of Networks Network Classification Layered Network Model
Communication Networks Outline • Why need networks • History of Networks • Network Classification • Layered Network Model 9
History of Internet 1966, national physical lab(nPl)network in England A local area network (LAN pioneered the concept of packet switching 1969. interconnection of two nodes later became arpanet 1972, emergence of 1OMbps Ethernet (Lan), which is widely used today 1974. TCP/IP Protocol became an rfc and the first use of term“ Internet 1978, invention ofE-Mail by a 14-year-old boy named V.a Shiva ayyadurai 1982, IEEE 802 Standard Family
Communication Networks History of Internet • 1966, national physical lab (NPL) network in England – A local area network (LAN) – pioneered the concept of packet switching • 1969, interconnection of two nodes, later became ARPANET • 1972, emergence of 10Mbps Ethernet (LAN), which is widely used today • 1974, TCP/IP Protocol became an RFC and the first use of term “Internet” • 1978, invention of E-MAIL by a 14-year-old boy named V. A. Shiva Ayyadurai • 1982, IEEE 802 Standard Family 10
History of Internet(cont) 1983, first TCP/IP based wide-area network started to operate (Pv4) 1984, open system interconnection(OSi) standardized by International Organization for Standardization (iso) 1991, Www was publicized at CErN (European Organization for Nuclear Research) 1994. Chinese connected to Internet 1995, IPv6 released by Ietf (Internet Engineering Task Force) 1998, IG-Ethernet(applied to metro area networks 2003, China Next Generation Internet(CNGI, IPv6 network) Tencent Taobao
Communication Networks History of Internet (cont’) • 1983, first TCP/IP based wide-area network started to operate (IPv4) • 1984, open system interconnection (OSI) standardized by International Organization for Standardization (ISO) • 1991, WWW was publicized at CERN (European Organization for Nuclear Research) • 1994, Chinese connected to Internet • 1995, IPv6 released by IETF (Internet Engineering Task Force) • 1998, 1G-Ethernet (applied to metro area networks) • 2003, China Next Generation Internet (CNGI, IPv6 network) • … Tencent, Taobao, … 11