1. Lesson 7 – THE BUSINESS OF NETWORKING

2. TCP/IP and UDP Other Internet protocols Important Internet protocols OVERVIEW

3. Internet Protocol (IP): Internet Protocol defines how Network data is addressed from a source to a destination and in which sequence the data should be reassembled at the receiving PC. TCP/IP AND UDP

4. Transmission Control Protocol (TCP): Is a higher-level protocol that operates at the Transport layer of the OSI model. Manages connections between computers. Messages are carried (encapsulated) in IP datagrams. TCP/IP and UDP

5. User Datagram Protocol (UDP): Serves the same role as TCP, but offers fewer features. Supports the resending of unreceived packets to the destination. Is much faster for trivial Network communications. Does not offer error-checking/handling features. TCP/IP and UDP

6. Both TCP and UDP support ports or application-specific addresses, to which packets are directed. TCP and UDP ports

7. IP packets include addresses that uniquely define every computer on the Internet. The addresses are used to route packets from a sending node to a receiving node. IP addressing

9. IP packet fields: Version Header length Type of service Total length Identification, flags, and fragment offset Time to live IP addressing

10. IP packet fields: Protocol Header checksum Source IP address Destination IP address Options and padding Data IP addressing

11. Addresses are 32 bits long. They are divided into four octets, each one a byte long. In decimal notation, IP addresses are expressed as xxx.xxx.xxx.xxx The numbers 0, 127, and 255 are usually reserved for special purposes. IP addressing

12. ICANN: Internet Corporation for Assigned Names and Numbers. Administers Addresses on the Internet. IP addressing

13. 3 major classes of addresses: Class A Class B Class C IP addressing

14. ICANN assigns a number: In the first octet (Class A). In the first two octets (Class B). In the first three octets (Class C). IP addressing

15. 2 main components: Network ID (netid) Host ID (hostid) IP subnettting

16. Netid: Identifies the Network. Hostid: Identifies each node on the Network. IP subnettting

17. Subnet masks use contiguous 1s from left and to right. Hostid portion contains contiguous 0s, from right to left. The portion of the hostid that is subnet-masked cannot consist of all 0s or all 1s. Subnet masks

19. Domain Name System (DNS) Dynamic Host Configuration Protocol (DHCP) Hypertext Transfer Protocol (HTTP) File Transfer Protocol (FTP) NetNews Transfer Protocol (NNTP) Telnet Simple Mail Transfer Protocol (SMTP) Voice Over IP (VoIP) OTHER INTERNET PROTOCOLS

20. Common domain types: edu (educational institutions) gov (governmental entities) mil (military entities) net (Internet-related entities) org (nonprofit entities) ‘xx’ (different countries) Domain Name System (DNS)

21. Entities are free to add other names to the beginning of the domain name. The first portion of a domain name indicates the service being connected.

22. Domain Name System Domain names are resolved to IP addresses through the use of name servers.

23. Dynamic Host Configuration Protocol (DHCP) DHCP services: Run on a DHCP server. Control a range of IP addresses called a “scope”. “Lease” addresses to a client.

24. Hypertext Transfer Protocol (HTTP) Controls transactions between a web client and web server. Is an application-layer protocol. Is fundamentally an insecure protocol. Secure HTTP (S- HTTP) or Secure Sockets Layer (SSL) provide web Networking security.

25. File Transfer Protocol (FTP) Acronym for: File Transfer Protocol File Transfer Program

26. File Transfer Protocol (FTP) FTP is an application-layer protocol used to send and receive files between an FTP client and an FTP server.

27. File Transfer Protocol (FTP) An FTP transfer is usually done with the FTP program or a program that can use the protocol. Transfers are either text or binary-based.

28. NetNews Transfer Protocol (NNTP) NetNews (Usenet) is a set of discussion groups devoted to an extremely wide variety of topics.

29. NetNews Transfer Protocol (NNTP) Main branches are: Alt Comp Gov Rec Sci

30. NetNews Transfer Protocol (NNTP) Groups: Public - echoed to other Usenet servers. Private - hosted by an organization.

31. Telnet Allows a remote terminal session to be established with an Internet host. Remote users have access similar to what they would have at a terminal connected directly to the host computer.

32. Telnet Telnet is a session-layer protocol in the OSI Model. Telnet software must be running on both the host and client computer.

33. Simple Mail Transfer Protocol (SMTP) Sends and receive e-mail messages from one e-mail server to another. Defines a dialog between a sending and receiving system.

34. Simple Mail Transfer Protocol (SMTP)

35. Voice Over IP (VoIP) Transmits voice and facsimile information over IP-based Networks. Allows analog voice data to be digitized, encapsulated into IP packets, and then transmitted.

36. Voice Over IP (VoIP) Advantages: Efficient use of available connections. Connections are packet-oriented.

37. Voice Over IP (VoIP) Disadvantages: No guaranteed delivery. Packets arrive out of sequence. Quality of Service (QoS) not widely implemented.

38. IMPORTANT INTERNET PROTOCOLS Novell’s IPX/SPX NetBIOS and NetBEUI protocols AppleTalk

39. Novell’s IPX/SPX IPX can be used on any popular Network media. IPX addresses are dynamically and automatically negotiated with the server at the login.

40. Novell’s IPX/SPX IPX Network address has: A 32-bit Network address. A 48-bit node address. 16 bits for connection ID. Theoretically allows for 281 trillion nodes on each of 16 million Networks

41. NetBIOS and NetBEUI protocols Neither protocol is routable. They are suitable only for small LANs that do not rely on routers between LAN segments. NetBIOS can be encapsulated within TCP/IP packets on Windows NT Networks.

42. AppleTalk AppleTalk Phase II: Allows the routing of AppleTalk packets. Can run over Ethernet, Token Ring, or LocalTalk media.

43. SUMMARY TCP/IP and UDP: Transmission Control Protocol (TCP): User Datagram Protocol (UDP) TCP and UDP ports IP addressing IP subnettting Subnet masks

44. Summary Other Internet protocols: Domain Name System (DNS) Dynamic Host Configuration Protocol (DHCP) Hypertext Transfer Protocol (HTTP) File Transfer Protocol (FTP) Netnews Transfer Protocol (NNTP) Telnet Simple Mail Transfer Protocol (SMTP) Voice Over IP (VoIP)

45. Summary Important Internet protocols: Novell’s IPX/SPX NetBIOS and NetBEUI protocols AppleTalk