1. Data Communication And Internet Technology
Chapter 5
Data Communication
And
Internet Technology

2. Purpose
Understand the fundamental networking concepts

3. Agenda Network Concepts Communication Protocol TCP/IP-OSI Architecture
Network Types
LAN
WAN
Public Switched Data Network
Virtual Private Network
Network Comparison
Internet
Domain Name System
IP Addressing Schemes
Security
Discussion and Case Study

4. Network Concepts
A collection of computers that communicate with one another over transmission lines
Types
Local area networks (LANs): connects computers in a single geographic location
Wide area networks (WANs): connects computers at different geographic sites
Internet: a network of networks

5. Communication Protocol
Protocol: a standard means for coordinating an activity between two or more entities
Communications protocol: a means for coordinating activity between two or more communicating computers
The communication protocol is broken into levels of layers
Two machines must agree upon and follow the protocol for exchanging the message

6. TCP/IP-ISO Architecture - I
International Organization for Standardization (ISO): Reference Model for Open Systems Interconnection (OSI)
Internet Engineering Task Force (IETF): Transmission Control Program/Internet Protocol (TCP/IP)
TCP/IP-ISO architecture: five layers

7. TCP/IP-ISO Architecture - II
Layer 5 (Application): communication rules between two applications
Simple Mail Transfer Protocol (SMTP) for
Hypertext Transfer Protocol (HTTP) for processing Web page (sites and users)
File Transfer Protocol (FTP) for copying file between computers

8. TCP/IP-ISO Architecture - III
Layer 4 (Transport): communication rules between two host computers
Transmission Control Program (TCP)
Sending functions: break data into segments, add To and From address, and
Receiving functions: provide reliability by sending acknowledgement, and translate the format, assemble segments into data

9. TCP/IP-ISO Architecture - IV
Layer 3 (Internet): communication rules of routing packets across the Internet
Internet Protocol (IP)
Functions: package each segment into a packet, place IP data in in the packet, add To/From data

10. TCP/IP-ISO Architecture - V
Layer 2 (Data Link): communication rule for transmitting data within a single network
Functions: package packets into frames
Layer 1 (Physical): communication rule between adjacent device connected by a transmission medium

11. Terminology
Architecture: an arrangement of protocol layers with their associated tasks
Protocol: set of rule to accomplish the tasks
Program: software implementing the protocol
Web: sub set of Internet with users and sites to process protocol
Internet: communication structure
Browser: a program implementing the HTTP of the TCP/IP-OSI architecture (Netscape and Microsoft Internet Explorer)

12. TCP/IP-OSI Application Example

13. Network Types
LAN: local area network
WAN: wide area network

14. LAN - I
A group of computers connected together on a single company site and operated by the company
Equipments
Network interface card (NIC) or onboard NIC: an unique identifier named MAC (media access control) address
Unshielded twisted pair (UTP) cable with RJ-45 connecter
Optical fiber cable with ST and SC connectors

15. LAN - II IEEE (Institute for Electrical and Electronics Engineers)
Protocol: IEEE or Ethernet
Hardware characteristics (which wire carries which signals)
Package and process message over LAN
Operate on Layer 1 and 2
10/100/1000 Ethernet (Mbps)
Bits for communications speeds and bytes for memory sizes

16. Local Area Network

17. NIC Interface Card

18. Unshielded Twisted Pair (UTP) Cable

19. Optical Fiber Cable

20. LAN - III Wireless LAN Wireless NIC (WNIC)
IEEE g protocol to connect to an access point (AP) and IEEE 802.3

21. Wireless Access Standards

22. Wireless LAN

23. WAN Connects computers located at physically separated sites
Internet service provider (ISP)
Provide customer a legitimate Internet address.
Serve as the gateway to the Internet
Communicate between sending computer and Internet
Connecting computer and ISP
Telephone line
DSL (digital subscriber line)
Cable TV line

24. WAN - Equipment Modem Modem types
Convert data between digital and analog
Narrowband with speed less than 56 kbps and Broadband with speed over 256 kbps
Modem types
Dial-Up modem
Narrowband
Point-to-Point Protocol (PPP)
DSL modem
Permanent connection and one more line for telephone conversation
Asymmetric digital subscriber line (ADSL) for home and small business with slow upload speed with 256 kbps and faster download speed ranging from 256 to 768 kbps
Symmetric digital subscriber line (SDSL) for advanced users and larger business with Mbps performance level guarantees
Cable modem
Permanent connection and one more line for TV
10 Mbps download speed and 256 kbps upload speed

25. Analog vs. Digital Signals

26. Personal Computer (PC) Internet Access

27. WAN - Equipment Access devices
Switch (Layer 2)
Router (Layer 3)
Lease lines from telecommunication company
T1 line with Mbps speed
T3 line with Mbps speed
Optical fiber cable-768 with 40 Gbps
Point-to-Point Protocol (PPP)

28. Transmission Line Types, Uses, and Speeds

29. WAN – Public Switched Data Network
Public switched data network (PSDN)
Developed and maintained by a vendor for selling time to other company
Shown as a cloud in the map or diagram
User must have a leased line connecting to PSDN as point of presence (POP)
PSDN types
Frame Relay with 56 kbps to 40 Mbps: slower and cost less but simple and easy to support
Asynchronous transfer mode (ATM) with 1 to 156 Mbps: faster and cost more but transmitting data and voice
Ethernet with 10 to 40 Gpbs

30. Wide Area Network Using PSDN

31. WAN – Virtual Private Network
Virtual private network (VPN): a private internet as a private point-to-point connection
Tunnel: a virtual, private pathway over a public or shared network from the VPN client to the VPN server
Encrypted message
Remote access

32. Remote Access Using VPN

33. Wide Area Network Using VPN

34. Network Comparison Setup costs Operational costs Performance
Equipment: lines, switches, routers, and access devices
Labor
Operational costs
Lease fees for line and equipment
ISP charges
Training
Maintenance: problem diagnosis, repair, and updating
Performance
Speed: line and equipment
Latency: transmission delay due to congestion
Availability: service outages
Loss rate: transmission problem
Transparency
Performance guarantee: availability, error rate, speed, etc.
Growth potential
Contract commitment period
Management time
Financial risk
Technical risk

35. Summary of LAN and WAN Networks

36. Internet Network address
Physical or MAC address in Layer 2 program: permanent and unique
Logical or IP address in Layers 3, 4, and 5: not permanent, such as
Public IP address used on the Internet to major institutions in blocks assigned by Internet Corporation for Assigned Names and Numbers (ICANN)
Private IP address used within private networks and internets
DHCP server has Dynamic Host Configuration Protocol (DHCP) to assign a temporary IP address for accessing the Internet
Network Address Translation (NAT): The process of changing public IP addresses into private IP addresses, and the reverse

37. Domain Name System Convert user-friendly name into their IP address
domain name: any registered, valid name with ICANN
resolving the domain name: the process of changing a name into its IP address
ICANN has 13 computer as root servers for maintaining a list of IP addresses of servers to resolve each type of TLD in the world
Top-level domain (TLD)
Non-U.S. is the two letter abbreviation for the country
U.S. is the type of organization
Uniform resource locator (URL): document’s address on the Web
Domain name resolvers store the correspondence of domain names and IP address

38. IP Addressing Schemes IPv4 and IPv4
32 bits divided into four groups of 8 bits, and a decimal number represents each group
The largest decimal number between the period is 255 (0 – 255)
IPv6
128 bits due to the growth of the Internet
Currently both IPv4 and IPv6 are used on the Internet

39. Security Encryption algorithms: DES, 3DES, AES Key HTTPS
Symmetric encryption
Asymmetric encryption: public key and private key
HTTPS
Secure Socket Layer (SSL) and Transport Layer Security (TLS)
Public key, private key and symmetric encryption

40. Summary TCP/IP-OSI five layers Public switched data network (PSDN)
Application layer
Transport layer
Internet layer
Data link layer
Physical layer
Public switched data network (PSDN)
Dynamic Host Configuration Protocol (DHCP) to assign a temporary IP address for accessing the Internet
Domain name

41. Discussion Problem solving (121a-b) Opposing forces (129a-b)
What are the new opportunities for the business generated by the Internet?
What are the new threats for the business generated by the Internet?
Opposing forces (129a-b)
State your opinions related to the negative impact on the society when everyone is connect through the Internet.
Security (133a-b)
State the impacts on the society and business from the government having an decryption method to decode everything over the Internet.
Ethics (141a-b)
State the impacts from the employee’s private usage of company’s computer facility.
Reflections (143a-b)
How should you react properly from not getting lost from this Internet age?

42. Case Study
Case 5-1 ( ) Network Services: questions 1, 3, 4, 5, 6, 9, and 10

43. Points to Remember Network Concepts Communication Protocol
TCP/IP-OSI Architecture
Network Types
LAN
WAN
Public Switched Data Network
Virtual Private Network
Network Comparison
Internet
Domain Name System
IP Addressing Schemes
Security
Discussion and Case Study