The Big Picture

1. The Big Picture Bond University, IT School Tan AlamAcknowledgment: Alexander Zangerl

2. PART A: INTERNET Internet History • http://www.zakon.org/robert/internet/timeline/ • 1969: ARPA • ARPA: Advanced Research Projects Agency (US) • Commissioned by DoD during cold war • Control over network to service Nuce War • public teleph net was vulnerable • packet-switching network • 4 node ARPANET (UCLA, SRI, UCSB, UoU)

3. Internet History • 1975 • First ARPANET mailing list, MsgGroup, is created by Steve Walker. • John Vittal develops MSG, the first all-inclusive email program providing replying, forwarding capabilities.

4. Internet History • 1983: Name server developed at Univ of Wisconsin, no longer requiring users to know the exact path to other systems • 1985: NSF (US national science foundation) links supercomputers & universities • late 80's • first commercial ISPs

5. Internet History • 1990: ANS (Advance Networks and Services) took over NSFNET, • Updated 1.5 Mbps links to 45 Mbps • Early 90's: NSF awarded contract to PacBell, Ameritech, MFS, Sprint to build NAPs -- to ease transition and make sure every regional network could communicate with every other regional network

6. Internet History • Mid 90's • explosive growth of the net • Mosaic 1, web browser (hit the market in 93, images) • Netscape 1 was founded in Dec 94, Mozilla • Sun: Java was invented

7. Internet History • Late 90's • net abuse & censorship • Microsoft: tries to reinvent/control/rule Browser War http://www.quirksmode.org/browsers/history.html Microsoft targeted web designers with little knowledge • Reflow of pages

8. What is the Internet? • A global network of networks • network connecting hosts • hosts can transparently communicate with other hosts • provide services • access services • based on IP packet switching

9. Involved Parties • User PC • at home/company • multimedia (sound, video, graphics) • User Communication Equipment • Modem (plugs into phone, 56 kbit/s) • Cable modem (plugs into Cable TV outlet) 2-10Mbit • ISDN adapter (plugs into ISDN outlet) 2x 64kbit

10. Parties (cont'd) • Organisation Communication Equipment • Ethernet card (plugs into LAN, 10, 100Mbit) • Token Ring card (plugs into LAN) • company firewall (hopefully well configured) • Router plugs into leased line (LL) etc.

11. Parties (cont'd) • ISPs (Internet Service Provider) • Dial-up infrastructured, lease line infrastructure • backbone (Ethernet, optic fibre, satellite links) • services • transport of your data to and from the internet • DNS, mail, web hosting • national peering (NAPs) • international connectivity/peering

12. Parties (cont'd) • Carriers • backbone providers • AT&T, Sprint, MCI/WorldCom, C&W, Qwest • optic fibre (Gbits) • switches • interconnection points (bridges, hubs, repeaters etc.)

13. Online providers (classes) • Carriers (Sprint, AT&T, C&W, Qwest) • only (leasable) lines • Internet Service Provider (BigPond, ...) • IP traffic & routing, essential services (DNS) • Content Service Providers (AOL, MSN) • IP traffic and content • online news, ....

14. Internet Administration • No central authority • organisational bodies • IANA (provides DNS, http://www.iana.org/) • ICANN (http://www.icann.org/ new assignment authority) • IETF, engineering task force (www.ietf.org) • W3O, world wide web consortium (http://www.w3.org/) • CERT (Internet security)

15. Internet Standards • RFCs, • request for comments • published concept, technique or protocol as draft • IETF gives comments • work groups, related issues • review process • publishing queue of editor • RFC2223

16. Internet Impact • accessibility of information • experts, governments, university • speed of technology change • new industries • ISPs, web agencies, consulters, application providers, portals • e-commerce (C2B, B2B) • reseller chains, interfacing/tracking customers

17. Internet Impact • Results • decentralized • not really easy to control • but all governments would like to... • lots of anti-privacy laws...

18. Netiquette • Conduct guidelines • RFC1855 • Mail: be concise, don't fire mails in anger • Be proud of what you say • Web: be careful when doing e-commerce • VideoConferencing: wear shirts ;-)

19. PART B • Binary to Decimal • Decimal to Binary • Hex • https://james.bond.edu.au/courses/inft12230/043/Labs/week1.html • Gates: AND, OR

20. Measuring Data

21. Throughput and Bandwidth • Throughput - the amount of data that a communications channel can carry during a given period of time. • The physical nature of every communications channel determines its potential throughput. • Bandwidth - a measure of the difference between the highest and lowest frequencies that a media can transmit.

22. Terminology • Standalone workstation - a workstation that is not connected to a network, but relies on its own hard disk for operating system files, data storage and applications. • Client - a workstation or Node/Host connected to a network. A person whose workstation is part of a network may also be called a client, or that person may be known more informally as a user. • Server – special purpose Nodes/Hosts on a network that can store shared data and programs. They can also perform management functions, such as determining which users have access to certain programs.

23. Terminology

24. Requirements for Connectivity

25. Requirements for Communications • Node - any device (for example, a server, client, or printer) that can receive a transmission over a network. To receive data, each node must have a unique address, or identifying number. • Protocol - a policy/standard that governs how the parts of a network communicate

26. Servers • Server - A Node/Host on the network that manages shared resources. • Network operating system (NOS) - software that can manage not only data, but also users, groups, security, and applications on the network.

27. LANS, MANS, and WANS • Local area network (LAN) - a network of nodes (computers and other devices) that is confined to a relatively small space, such as one building or even one office. Usually under local administration control and owned by the organization.

28. LANS, MANS, and WANS • Metropolitan area network (MAN) - a network that connects nodes and network segments in multiple buildings in a region. Usually connecting sub-networks (subnets) or small networks together to form a larger network. These networks are usually owned by the one company or connected together for business reasons. Administration can be centralized or distributed – in-house or independent.

29. LANS, MANS, and WANS • Wide area network (WAN) - a network that connects two or more geographically distinct LANs into one larger network enabling the nodes on all networks to communicate with each other

30. LANS, MANS, and WANS

31. LANS, MANS, and WANS

32. LANS, MANS, and WANS

33. The Internet • The Internet is a unique WAN not only because of its size, but also because of its diversity. • It may transmit confidential information between two offices within the same organization, or it may transmit public records to anyone who requests them. • To connect users from around the globe, the Internet relies on a hierarchical structure of connection points, just as the PSTN relies on a hierarchy of central offices. • An Internet Service Provider (ISP) is a company that operates a network and provides consumers with a link to the Internet.

34. The Internet

35. Switching • A method of establishing connections and sending information between nodes on a network • Used in both voice and data communication • Circuit, message, packet switching,

36. Circuit Switching • Establishing a connection between two devices on a network, before they begin transmitting data. • All data follows the same path (set up) between the two devices • Bandwidth is reserved and dedicated to the path until the connection is terminated. • Can be inefficient use of bandwidth, good for real-time applications eg.voice, video, etc.

37. Telephone Circuit Switching

38. Message Switching • ‘Store and Forward’ • Same path • Not dedicated connection –allows sharing of channels • Requires intermediate nodes to have storage capacity • Not often used except for E-mail

39. Message Switching

40. Packet Switching • Most common • Large data/message is split into specific size (max) Packets • Each packet has the source and destination address and its place in the larger message • Each packet can travel a different path to the destination • All packets are reassembled back into the larger message at the final destination ONLY

41. Packet Switching • Advantages • Each packet can find the fastest path available (now) • Each packet can take a different path and not have to travel single file • Disadvantages • Some time is needed to reassemble packets into the larger message at the destination • Some packets may be delayed on their path – meaning the reassembly is delayed • Some packets may be lost on their path – meaning that some packets reach the destination but not all so reassembly is impossible • These time delays make it unsuitable for real-time applications

42. Packet Switching