Dr. Chen, Management Information Systems Chapter 6 Data Communication and the Cloud Jason C. H. Chen, Ph.D. Professor of MIS School of Business Administration

Dr. Chen, Management Information Systems

Chapter 6Data Communication and the

Cloud

Jason C. H. Chen, Ph.D.Professor of MIS

School of Business AdministrationGonzaga UniversitySpokane, WA 99258

[email protected]


GearUp Scenarios

Chapter 4: Hardware and Software• GearUp has important decisions to make about

critical software development projectChapter 5: Database Processing• GearUp does not have the easy access to data

needed to analyze vendor quality and costsChapter 6: Data Communication and the Cloud• GearUp needs to make decisions about building

infrastructure for the next stage of its growth• GearUp needs to understand advantages and

disadvantages of cloud-based computing

2


GearUp: “No, I Mean 25 Cents an Hour.”

• Gearup’s Web hosting costs rising rapidly• Lucas suggests provisioning Web servers and

databases in the cloud• Provision server resources by the hour• Costs: $50/mo plus 25-cents per hour for

processing time used• Could yield huge savings


Topics in Networks

• Three popular networks– LAN– MAN– WAN and– Internet


Study Questions

Q1: What is a computer network?

Q2: What are the components of a LAN?

Q3: What are the fundamental concepts you should know about the Internet?

Q4: What processing occurs on a typical Web server?

Q5: Why is the cloud the future for most organizations?

Q6: How can organizations use the cloud?

Q7: 2022?


• Computer network is a collection of computers that communicate with one another over a variety of transmission lines.

• Three basic types of networks: LAN, WAN, and Internet.• What are the alternatives for a WAN?(video)

Figure 6-1 Major Network Types

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Q1: What Is a Computer Network?

http://media.pearsoncmg.com/ph/bp/bp_akamai/kroenke/videos.php?title=Chapter%206-%20What%20are%20the%20alternatives%20for%20a%20WAN?&clip=pandc/kroenke/Ch_06_1.flv


• WANs connect computers located at physically separated sites by obtaining connection capabilities from a third-party, typically an Internet Service Provider (ISP).

• Three primary functions of an ISP are to:

1. Provide users with a legitimate Internet address

2. Serve as a gateway for users to connect to the Internet

3. Help pay for the Internet by collecting money from customers and using it to pay access fees and other charges

Connecting to the InternetWhat Are the Alternatives for a WAN?

7


What is a computer network?

• Network: a communications, data exchange, and resource-sharing system created by linking two or more computers with communication standards, or protocols, so that they can work together

• Three major types of networks: – Local area network (LAN): computers connected at a

single physical location, such as networks on GU campus. – Wide area network (WAN): Computers connected between

two or more separated sites (locations)– The Internet and internets: Networks of networks


• Additional characteristics of networks: LAN communication lines reside on-premises, making

it easier for a business to locate a network wherever it chooses.

WAN communication lines are owned by a third-party vendor. A business contracts with vendor to use its WAN lines.

Each type of network uses protocols which are sets of rules that two devices use to communicate with each other.

What Is a Computer Network?

9


Q2: What Are the Components of a LAN? SOHO

LAN

Figure 6-2 Typical Small Office/Home Office (SOHO) LAN


• Components are usually located within a half mile of each other.

• A switch is a special-purpose computer that receives and transmits messages to computers in the LAN.

• A network interface card (NIC) is a hardware component that connects each device’s circuitryto a cable allowing protocols tosend data across the LAN.

• Most computers todayinclude an NIC.

What Are the Components of a LAN?

Fig 6 (extra): Local Area Network (LAN)11


Fig 6 (extra): Local Area Network (LAN)

What are the components of a LAN?

A media access control (MAC) address serves as a unique identifier for each NIC on a LAN.


• Media access control (MAC) address serves as a unique identifier for each NIC on a LAN.

• Unshielded twisted pair (UTP) cables, shown on left, are one way to connect devices to a LAN.

• Optical fiber cables, shown on right, connect devices to a LAN using fiberglass wires to transmit signals which are light rays. Cladding contain the signals. Optical fiber carries more traffic than UTP cables.

Wired Connectivity:What Are the Components of a LAN?

Fig 6-(extra) Unshielded Twisted Pair (UTP) Cable Fig 6-5 Optical Fiber Cable

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Question

• In order for a printer or laptop to connect to a wireless LAN they must have a(n)– NIC or– Something else?


• IEEE 802.11 wireless protocol uses wireless NICs (WNIC) to connect devices to networks similar to how wired NICs operate.

• Figure depicts a combination of NICs and WNICs on a LAN.

• Access points (AP) use

802.3 protocol to communicate with a switch and 802.11 protocol to send and receive wireless traffic.

Wireless Connections:What Are the Components of a LAN?

Fig Extra: LAN with Wireless 15


LAN Protocol

IEEE 802.3• Wired LAN• 10/100/1000 Mbps• Ethernet

IEEEE 802.11• Wireless LAN• 802.11n• Bluetooth


• The IEEE, Institute for Electrical & Electronics Engineers, is a committee that creates and publishes protocols and standards used by virtually every network.

• IEEE 802.3, or Ethernet, protocol is used by all LAN devices. It specifies hardware characteristics and describes how messages are packaged and processed.

• Onboard NICs in new PCs support10/100/1000 Ethernet protocol which describes transmission rate speed.

• Communication speeds are expressed in bits like 1,000,000 for megabits.

What Are the Components of a LAN?

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Summary of LAN and WAN Networks

Figure 6-3 Network Technology Summary


• Connecting personal computers to an ISP requires that digital signals coming out of the computer are converted to analog signals. Analog signals coming into a personal computer must be converted to digital signals.

Comparison of digital and analog signals.

Connecting to the Internet

Fig 6-4 Analog Versus Digital Signals19

digital signal (0/1)

analog signal (wavy)


What are the alternatives for a WAN?

Fig 6-5 Personal Computer Internet Access

Modems are used to convert the signals back and forth as shown in the figure below.

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digital signalanalog signal


• 1. DSL (Digital Subscriber Line) modem shares a single communication line for a telephone and a personal computer. It’s much faster than a dial-up modem and allows a user to maintain a constant network connection with an ISP. Asymmetric DSL, ADSL, provides different upload/download speeds. Symmetrical DSL, SDSL, provides the same upload/download speeds.

• 2. Cable modem shares a single communication line for cable TV and a personal computer. It’s also faster than a dial-up modem and allows users to maintain a constant network connection. Because cable modems use a neighborhood distribution center,

transmission speeds vary based on the number of network users.• DSL and cable modems are considered broadband because their

transmission speeds exceed 256 kbps (narrowband is with the transmission speeds of less than 56kbps).

Two Ways connecting to an ISP(for Homes and Small Businesses)

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Q3: What Are the Fundamental Concepts You Should Know About the Internet?

Fig 6-6 Using the Internet for a Hotel Reservation


Video

• Cloud_Computing_bmis235(4m50s)

• TCP / IP - An animated discussion (6:12) • http://www.youtube.com/watch?v=RbY8Hb6abbg

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http://www.youtube.com/watch?v=RbY8Hb6abbg


What are the functions of the five TCP/IP?

• Throughout this chapter, and while you’re using the Internet, you’ll hear these terms used frequently. – Architecture is the arrangement of protocol layers with

each given specific tasks.– Protocols are sets of rules that accomplish tasks in each

layer.– Programs are specific computer products that

implement protocols.


Five Layers of TCP/IP Protocols

FiveLayers of TCP/IPProtocols

Application LayerApplication Layer

Transport (TCP) LayerTransport (TCP) Layer

Internet Protocol (IP) LayerInternet Protocol (IP) Layer

Physical LayerPhysical Layer

Software Developers

HardwareExperts

25

USERS?

Data Link LayerData Link Layer

Why TCP/IP Protocol?


TCP/IP Protocol Architecture

Fig 6-7 TCP/IP Protocol Architecture

This chart gives you the specific and broad functions of each layer in the TCP/IP-OSI architecture.

TCP or Transmission Control Protocol

• Breaks traffic up into packets and sends each one along its way

IP (Internet Protocol) Routers


TCP and IP Protocols:Middle Layers

• TCP or Transmission Control Protocol• Breaks traffic up into packets and sends each

one along its way

• IP (Internet Protocol)• Routers


IP Addressing

• Public IP Addresses • Identify a particular device on public Internet • Public IP addresses must be unique, worldwide• Assignment controlled by ICANN (Internet Corporation for

Assigned Names and Numbers)

• Private IP Addresses • Identify a particular device on a private network• Controlled by company operating network

• Major benefits1. Public IP: All devices on LAN share a public IP address.

2. Private IP address, need not register computer with ICANN-approved agencies.


Functions of the LAN Device

• Switch processing: IEEE 802.3 wired LAN traffic• Access-point processing: IEEE 802.11 wireless LAN

traffic• Translating between IEEE 802.3 and IEEE 802.11• Converting between Analog and Digital• Assigning private IP addresses• Converting IP address between private and public IP

addresses• Routing packets• And more …


Public IP Addresses and Domain Names

IPv4• Four decimal dotted notation like 165.193.123.253

Domain name•Worldwide-unique name affiliated with a public

IP address•Affiliation of domain names with IP addresses

is dynamic

URL (Uniform Resource Locator)


• Virtual Private Networks (VPNs) create the appearance of private point-to-point connections by using tunnels to create virtual, private pathways over the Internet.

• Figure below shows connections a VPN uses.

Virtual Private Networks (VPN)

Fig 6-9 Remote Access Using VPN: Actual Connections

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Fig 6-10 Remote Access Using VPN: Apparent Connection

Why Do Organizations Use Virtual Private Networks?

A VPN appears to be a direct connection between two sites as shown in this figure.

Software encrypts data as they pass through the VPN making them more secure. Then, decodes when user receives them.

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Fig 6-11 WAN Using VPN

Why Do Organizations Use Virtual Private Networks?

This figure shows how a WAN uses three different VPN tunnels to connect geographically separated users.

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Secure but costly !!!

One Solution: Web Server


Q4: What Processing Occurs on a Typical Web Server?

• Almost all e-commerce applications use the three-tier architecture, which is an arrangement of user computers and servers into three categories, or tiers (see Fig. 6-13).– User tier:

consists of computers, phones, and other devices that have browsers that request and process web pages.

– Server tier:consists of computers that run Web servers and process

application programs.

– Database tier:consists of computers that run a DBMS that processes requests

to retrieve and store data.


Fig 6-13 Three Tier Architecture

Three Tier Architecture for E-Commerce Applications


Linking Internal Databases to the Web

DATABASE TRENDS

N 36

Server tierDatabase tierUser tier


Web-Based Client/Server Database Architecture

Network

Web server

Database Server

Web Browser5. Retrieved data

4. Data query

7. Data-based Web page

8. Data-based Web page

1. Request for data-based Web page

6. Retrieved data

3. Data query

2. Request for data-based Web page

LegendCommunicationsBetween Web browserAnd Web server

CommunicationsBetween Web serverAnd database server


Watch the Three Tiers in Action!

Fig 6-12


Hypertext Markup Language (HTML)

Fig 6-15


XML, Flash, Silverlight, HTML 5

• XML (eXtensible Markup Language)• Fixes several HTML deficiencies• Program-to-program interaction over Web• Flash • Browser add-on for animation, movies, and other

advanced graphics inside a browser.• Silverlight• Browser add-on with greater functionality than

Flash• HTML 5.0 • Supports animation, movies, and graphics


Q5. Why Is the Cloud the Future for Most Organizations?

• Cloud Elastic leasing of pooled computer resources

over the Internet

• Elastic Dynamically increasing/decreasing a leased

resource programmatically in a short span of time, and only pay for resource used


Why Is the Cloud Preferred to In-House Hosting?

Fig 6-17 Comparison of Cloud and On-Site Alternatives


Why Is the Cloud Preferred to In-House Hosting? (cont’d)

Fig 6-17 Comparison of Cloud and On-Site Alternatives


When Does the Cloud Not Make Sense?

• Only when law or industry standard practices require physical control over the data

• Private cloud In-house hosting, delivered via Web service

standards


• Cloud computing Refers to a computing network on the Internet When you access a video from a site like

Facebook, you are accessing computing services in the cloud. You don’t know which server is processing your Facebook requests or which server is playing the video. You just know that somewhere in the cloud one or more servers are causing the video to be downloaded to your computer.

Clouds

http://en.wikipedia.org/wiki/Cloud_computing

Dr. Chen, Management Information Systems 46

Cloud Service

• Web Email• Online virus

detection• YouTube• Online Doc• Blogging• …



Another Video for Cloud Computing

http://www.salesforce.com/cloudcomputing/?fromSearch=true

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Q6. How Can Organizations Use the Cloud?

Fig 6-18 Three Fundamental Cloud Types

T/F: The most basic cloud offering is platform as a service (PaaS), which is the cloud hosting of a bare server computer or disk drive.

Answer: See page. 201



Q7: 2022?

Cloud computing benefit • Individuals on iCloud• Small groups using Office 365• Startups Using PaaS• Huge organizations using IaaS

New categories of products and services

Create new jobs?

Tele-action• Telediagnosis, telesurgery, telelaw enforcement



• End of Chapter 6


Documents

Dr. Chen, Management Information Systems Chapter 6 Data Communication and the Cloud Jason C. H. Chen, Ph.D. Professor of MIS School of Business Administration