1. Class Notes Overview of Internet Session B
CPT 123 Internet Skills
Class Notes
Overview of Internet Session B

2. Internet Services Telnet Service
Using the Telnet service entails establishing a Telnet session between your computer and the remote system you are trying to access

3. Internet Services
Telnet session - A connection to a host computer using the telnet program, which allows the remote computer to appear as a directly attached terminal.

4. Internet Services
The session has a client part, the Telnet program on your local system and a server part, usually a Telnet server running on the remote system

5. Internet Services
Once a session is established, the client and server programs work together to provide the user with a terminal window or session that allows the user to interact with the remote system

6. Internet Services
Usenet - A facility of the Internet, also called “the news,” that allows users to read and post messages to thousands of discussion groups on various topics.

7. Internet Services
Newsgroup - A forum for discussion of a specific topic in Usenet.

8. Internet Services
Discussion Group - A discussion group is a form of in which people who want to exchange information on a particular topic send to members of a list.
The Intranet Journal Web site offers robust discussion groups on Intranet topics.

9. Internet Services
Threaded Discussion - A threaded discussion is a listing of messages that follow a particular train of thought.
An excellent tool for keeping up on the latest trends and developments in technology.

10. Internet Services
Chat Room - A chat room works similar to in that a message is typed and conveyed electronically over the Internet or Intranet.
Text-based conversations
Message is received and responded to in real time

11. Internet Services
The recipient of the message is there to receive it and respond to it
As the recipient types response, it is visible on the sender’s computer screen
Can also involve multiple participants

12. Internet Services
Chat rooms can be used to facilitate teams whose members reside in various locations.

13. Internet Services
Spam - A Usenet posting that violates news etiquette by being indiscriminately sent to multiple newsgroups.

14. Internet Services
Video Conferencing - Video conferencing is a technology that allows people located in different locations to meet and communicate visually via the Internet or Intranet.

15. Internet Services
Internet Telephony - Internet telephony is the ability to transmit voice over the Internet, similar to telephone conversations.
Today’s hardware and software leave a lot to be desired

16. Internet Services
Whiteboarding - Whiteboarding is an Internet application in which two or more users in different locations can view and edit the same document on line at the same time.
Changes show up automatically on each user’s computer screen as they are made.

17. Internet Services
A different color is used for each user.

18. Internet Services
Push Technology - Push technology provides users with custom data sent directly to their computer desktops.

19. TCP/IP
Data is transmitted across the Internet through a series of protocols known collectively as TCP/IP (Transmission Control Protocol/Internet Protocol)
A protocol is an agreed upon set of conventions that define the rules of communication.

20. TCP/IP
The sending and receiving computers on the Internet follow the TCP/IP protocol to ensure that data is transmitted correctly
Data travels across the Internet through several levels of networks until it reaches its destination.

21. TCP/IP
messages arrive at the mail server from a remote PC or from a node on a LAN.
The message then leaves the local mail server and travels through a router (a special purpose computer) that ensures each message is sent to its correct destination.

22. TCP/IP
The mail message will pass through several networks to get to its destination.
Each network has its own router that determines how best to transmit the message closer to its destination.
The network router considers the traffic on the network.

23. TCP/IP
A message passes from network to network until it arrives at the destination network.
The message is then sent to the recipient, who has a mailbox on that network.

24. TCP/IP

25. TCP/IP TCP/IP applies to all types of data.
Data is sent across the Internet in packets.
Each packet is limited in size.
Rules for creating, addressing, and sending the packets are specified by TCP/IP.

26. TCP/IP TCP/IP is actually two separate protocols.
TCP is the portion that divides the file to be sent into packets.
TCP then numbers each packet so that the message can be reconstructed at the other end.

27. TCP/IP
IP is the portion that sends each packet on its way by specifying the address of the sending and receiving computers so that the routers can do their job.

28. TCP/IP The TCP/IP protocol is very clever.
The division of large files into smaller pieces ensures that no single file monopolizes the network.

29. TCP/IP
TCP/IP by dividing the file ensures that the data arrives correctly.
Static [noise] on a telephone line can be devastating when a file is transmitted and a byte or bytes are lost or corrupted.

30. TCP/IP
The larger the file the greater the chance of corruption, since the chance of noise being introduced is greater.
Small pieces and verification that the packets are received correctly, helps ensure data integrity.

31. TCP/IP
Only incorrect packets need to be sent again, not the entire file.
TCP/IP connections are expensive and most cannot justify the high cost of a permanent TCP/IP connection to the Internet.

32. TCP/IP
A standalone personal computer usually accesses the Internet through a dial-up connection via a modem.
This is a temporary connection known as a SLIP [Single Line Internet Protocol] or PPP [Point to Point Protocol] connection.

33. TCP/IP
SLIP or PPP enables full access to the Internet as long as the telephone connection is live.
Internet is built in layers around the TCP/IP protocol

34. TCP/IP

35. TCP/IP The sending computer
the application layer creates the message and passes it to the transport layer
the transport layer divides the message into packets
the Internet layer addresses the packets

36. TCP/IP
The network access layer then sends the message across the Internet to its destination.
The process is reversed at the receiving computer.
Each computer on the Internet must have TCP/IP drivers or stacks

37. TCP/IP
Each computer must also have a unique IP address that identifies the computer as a node on the Internet
IP addresses may be permanent or temporary [changes from session to session]

38. TCP/IP The IP address is composed of four numbers Each less than 256
Each separated by a period
Example
Each site on the Internet applies for a block of IP addresses

39. TCP/IP Mnemonic addresses rather than numeric IP addresses can be used
The network administrator assigns IP addresses to all devices on the network
The protocols are hardware independent

40. TCP/IP Numeric IP addresses are easy to process by a computer
However, individuals would rather use names [mnemonic equivalents]
Which is easier or webwilly.engr.iupui.edu?

41. TCP/IP
Domain Name System [DNS] provides the mnemonic for an IP address
DNS also ensures that every site on the Internet has a unique address

42. TCP/IP
DNS divides the Internet into a series of networks called domains which enable data to be sent across the entire Internet
Each site attached to the Internet belongs to one of the domains

43. TCP/IP Examples edu --- educational institutions
gov --- government entities
com --- commercial entities
mil --- military organizations
net --- network service providers
org --- nonprofit organizations

44. TCP/IP Large domains are subdivided into subdomains
Mnemonic names must be translated into IP addresses
A domain root server maintains information about IP addresses in its domain