telecommunications, the internet, and … the internet, and wireless technology eai with it ......

Lecture 19TIM 50 Autumn 2012Thursday November 29, 2012

TELECOMMUNICATIONS, THE INTERNET,AND WIRELESS TECHNOLOGY

Announcement

1. The grades for every assignment will be given in eCommons.2. It's important to check webpage to get the latest informationand assignments changes.

Final ExamDecember 10, Monday 0800 ‐1000AMFinal Review December 4 Tuesday in Class

Format is same as MidtermCovering Up to Midterm 25‐ %

After Midterm 75+ %

Final Exam Review 12/4 In Class

TELECOMMUNICATIONS, THE INTERNET,AND WIRELESS TECHNOLOGY

EAI with IT

Computer SystemsNetwork ArchitectureCommunications

Business Resource Applications

Summary of Previous Network Information Systems

Architecture

Internet,Web

Mobile Applications

Competitive Advantagesin the Business

General Review

• Fundamentals of Telecommunications• Networking Media, Devices, and Software• Wireless Telecommunications Technologies• Networks and Distributed Computing

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Networking Devices

• Modems– Modulates and demodulates signals – Cable modem

• Provides Internet access over a cable television network – DSL modem

• Provides high‐speed Internet service over telephone lines

• Network adapter– Computer circuit board, PC Card, or USB device

• Network interface card (NIC)• Wireless adapters

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Network Control Devices

• Hubs– Used as a central point for connecting a series of computers

• Switches– Fundamental part of most networks– Allow several users to send information at the same time

without slowing the network

• Repeaters– Connect multiple network segments

• Bridges– Connect two or more network segments

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Network Control Devices

• Gateways– Network points that act as an entrance to another network

• Routers – Can divide a single network into two logically separate networks

• Wireless access point– Receives and transmits data to wireless adapters

• Firewall – Device or software that filters the information coming onto a network, generally to increase security and remove unwanted traffic

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The Internet ?

A modem is a device that translates digital signals into analog form (and vice versa) so that computers can transmit data over analog networks such as telephone and cable networks.

FUNCTIONS OF THE MODEM

MODEMS

• Transmission speed

Modems are available in different transmission speeds, which are measured in BPS (bits per second) also called BAUD rate. Standard modems speeds: 9600 baud, 14400 baud, 28800 baud, 33600 baud, 56800 baud.

• Internal/External

Internal modems are electronic cards. An internal modem is installed in one of the computer's expansion slot. External modems are fully functioning external devices. The external modem is connected to a computer using a serialcable to one of the computer's serial ports, and draws power from an external power source.

Networks for Beginners: http://compnetworking.about.com/

HUBS

New devices ‐ hubs ‐ were introduced to simulate those characteristics. Simply put, the hub's major function is to replicate data it receives from one device attached to it to all others.

The original Ethernet LANs relied on certain physical characteristics of the cable carrying the network data (usually coaxial cable). New Ethernet technologies introduced new cable types that we unable to fulfill the original physical requirements.


REPEATERS

An illustration of a repeater at workThe electrical signal entering the repeater at one end is weakened.The repeater amplifies the electrical signals and resends the data.

A repeater is connected to two cable segments. Any electrical signal reaching the repeater from one segment, will be amplified and retransmitted to the other segment. A common problem in the networking world is that of weakening electrical signals. Electrical signals traveling through wires (such as copper wires used in most networks), weaken due to the wire's electrical resistance. This effect limits the lengths of the cable that can be used. A repeater will overcome this limit, when there is a need to connect two computers at a larger distance.


ROUTERS

• Routers connect two or more networks and forward data packets between them. When data arrives from one of the segments, the router decides, according to it's routing table, to which segment to forward that data.


GATEWAY

• "Gateway" is a term that was once used to refer to a routing device. Today, in the TCP/IP world, the term "router" is used to describe such a device.

The term gateway now refers to special‐purpose devices, that perform protocol conversions. Gateways implement application layer conversions of information received from various protocols.

• Examples of gateways found on today's markets are: – VocalTec Gateway: A gateway that converts human speech traveling on

analog phone lines into local area network protocol data, and visa‐versa.

– RadVision Gateway: Converts video from digital phone lines into local area network protocol data, and visa‐versa.


EXAMPLE OF FIREWALL

• Firewalls are systems that establish access control policies among networks. They can block information from entering a network or from getting out of that network, they can permit different users to perform different kinds of operations, according to the user's authorizations.


What is a computer network?

Two or more connected computers

Major components in simple networkClient computer Server computerNetwork interfaces (NICs)Connection mediumNetwork operating systemHub or switch

RoutersDevice used to route packets of data through different networks, ensuring that data sent gets to the correct address

Illustrated here is a very simple computer network, consisting of computers, a network operating system residing on a dedicated server computer, cable (wiring) connecting the devices, network interface cards (NICs), switches, and a router.

COMPONENTS OF A SIMPLE COMPUTER NETWORK

Components of networks in large companies

Hundreds of local area networks (LANs) linked tofirmwide corporate networkVarious powerful servers

Web siteCorporate intranet, extranetBackend systems

Mobile wireless LANs (Wi‐Fi networks)Videoconferencing systemTelephone networkWireless cell phones

Today’s corporate network infrastructure is a collection of many different networks from the public switched telephone network, to the Internet, to corporate local area networks linking workgroups, departments, or office floors.

CORPORATE NETWORK INFRASTRUCTURE

Key networking technologies

Client/server computingDistributed computing modelClients linked through network controlled by network server computerServer sets rules of communication for network and provides every client with an address so others can find it on the networkHas largely replaced centralized mainframe computing

The Internet: Largest implementation of client/server computing

Networking Software

• Networking software– Monitors the load, or amount of traffic, on the network

– Provides error checking and can often indicate problems and possible solutions

– Can provide data security and privacy

• Network administrator or systems administrator– Person responsible for setting up and maintaining the network

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Wireless Fidelity and WiMAX

• Wireless fidelity (Wi‐Fi)– Makes use of access points to wirelessly connect users to networks within a range of 250–1000 feet (75‐300 meters)

• WiMAX– Known as IEEE 802.16– Faster and longer range than Wi‐Fi– WiMAX antenna has 31‐mile range

• Perfect for city‐wide Internet access

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Bluetooth

• Enables digital devices to communicate directly with each other wirelessly over short distances

• Communicates at speeds of up to 1 Mbps within a range of up to 33 feet (10 meters)

• Can connect devices to a computer network using access points like Wi‐Fi

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Bluetooth : 33 feetWiFi :1000 feetWiMax : 31 mile

Radio Frequency Identification (RFID)

• Uses tiny transponders in tags that can be– Attached to merchandise or other objects – Read using an RFID transceiver or reader for the purpose of identification

– Primarily used to track merchandise from supplier to retailer to customer

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Computer Networking Concepts

• Nodes– Devices attached to a network

• Workstations– Computers attached to a network

• Local resources – Files, drives, or other peripheral devices connected to the workstation and accessible via the network

• Network or remote resources– Workstation accesses over the network– Transparency provides user‐friendly environment

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Distributed Computing

• Distributed Computing– Multiple remote computers working together

• Database servers– Store databases and respond to queries

• File servers– Store files and deliver them to users upon request

• Application servers– Store programs and deliver them to desktops when users click the icon

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• Blade computing– Cheaper alternative– Takes advantage of the fact that at any one time, 30% of system PCs are not being used

• PCs are replaced with thin clients– Keyboard, mouse, display, unit to connect the device to the server

– Thin clients cost less than half the cost of a PC

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A blade server is a stripped‐down server computer with a modular design optimized to minimize the use of physical space and energy.

IBM HS20 blade server


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Network Types

• Personal area network (PAN)– Interconnecting personal information technology devices– Typically wireless

• Local Area Network (LAN)– Connects computer systems within same building – Can use various designs or topologies

• Intranet – Uses protocols of the Internet and the Web within the confines

of a private network• Virtual Private Network (VPN)

– Enables private Internet communications

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Network Types

• Metropolitan area network (MAN) – Connects networks within a city or metropolitan‐size area into a larger high‐speed network

• Wide area network (WAN)– Connects LANs and MANs between cities, across country, and around the world

• Global Networks– A WAN that crosses an international border (transborderdata flow)

– Data havens have few restrictions on telecommunications or databases

• Electronic Data Interchange (EDI)– Connects corporate computer systems

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The three basic network topologies are the star, bus, and ring.

NETWORK TOPOLOGIES

NETWORK TOPOLOGIES

Network Types

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Network Types

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Networking and communication TrendsConvergence:

Telephone networks and computer networks converging into single digital network using Internet standardsE.g. cable companies providing voice service

Broadband:More than 60% U.S. Internet users have broadband access

Broadband wireless: Voice and data communication as well as Internet access are increasingly taking place over broadband wireless platforms

TelecommunicationsandNetworkinginToday’sBusinessWorld

Management Information Systems, Sixth Edition 40

Protocols

• Protocol: set of rules governing Communication between computers

• Some protocols are designed for WANs, LANs, and wireless communications

• Most important set of protocols for telecommunications and networks is called TCP/IP

Key networking technologies (cont.)

TCP/IP and connectivityConnectivity between computers enabled by protocolsProtocols: Rules that govern transmission of information between two pointsTransmission Control Protocol/Internet Protocol (TCP/IP)

Common worldwide standard that is basis for InternetDepartment of Defense reference model for TCP/IP

Four layers1. Application layer2. Transport layer3. Internet layer4. Network interface layer

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TCP/IP

• TCP stands for Transmission Control ProtocolTCP software breaks messages into packets, hands them off to the IP software for delivery, and then orders and reassembles the packets at their destination

• IP stands for Internet ProtocolIP software deals with the routing of packets through the maze of interconnected networks to their final destination

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TCP/IP (cont.)

• UDP stands for User Datagram Protocol

– It is an alternative to TCP

– The main difference is that TCP is highly reliable, at the cost of decreased performance, while UDP is less reliable, but generally faster

Layers in the TCP/IP Protocol Suite

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Open Network Systems

• The International Organization for Standardization (ISO) established the Open Systems Interconnection (OSI) Reference Model

• Each layer deals with a particular aspect of network communication

Figure 15.5 The layers of the OSI Reference Model

TCP/IP and OSI model

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High‐Level Protocols

• Other protocols build on the foundation established by the TCP/IP protocol suite

– Simple Mail Transfer Protocol (SMTP)

– File Transfer Protocol (FTP)

– Telnet

–Hyper Text Transfer Protocol (http)


Ethernet

• Ethernet: LAN protocol using coaxial or Cat 5 or 6 twisted pair cable( Cable)

• Gigabit Ethernet: faster Ethernet connection of one Gbps or greater

• Devices on network contend with other devices for transmission time

• CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol ensures there are no collisions in transmission


Wireless Protocols

• IEEE 802.11: a family of wireless protocols known as Wi‐Fi (Wireless Fidelity)– Supports wireless communication within 100 meters of router

– 802.11 subtypes support various distances and speeds up to 248 Mbps

• Access point (hotspot): connection between wireless device and a wired network– Allows Internet access within range of equipment

Wireless Protocols (continued)

• Encryption: ability to scramble and encode messages– Uses encryption keys shared only between sender and receiver

• Bluetooth: allows devices to communicate within 10 meters– Transmits voice and data– Considered a PAN technology


Wireless Sensor Networks (WSNs)

Networks of hundreds or thousands of interconnected wireless devices embedded into physical environment to provide measurements of many points over large spaces

Devices have built‐in processing, storage, and radio frequency sensors and antennasRequire low‐power, long‐lasting batteries and ability to endure in the field without maintenance

Used to monitor building security, detect hazardous substances in air, monitor environmental changes, traffic, or military activity

The small circles represent lower‐level nodes and the larger circles represent high‐end nodes. Lower level nodes forward data to each other or to higher‐level nodes, which transmit data more rapidly and speed up network performance.

A WIRELESS SENSOR NETWORK

Radio frequency identification (RFID)

Use tiny tags with embedded microchips containing data about an item and location, and antenna

Tags transmit radio signals over short distances to special RFID readers, which send data over network to computer for processing

Active RFID: Tags have batteries, data can be rewritten, range is hundreds of feet, more expensive

Passive RFID: Range is shorter, also smaller, less expensive, powered by radio frequency energy

Radio frequency identification (RFID)

Common uses:

Automated toll‐collection

Tracking goods in a supply chain

Requires companies to have special hardware and software

Reduction in cost of tags making RFID viable for many firms

RFID uses low‐powered radio transmitters to read data stored in a tag at distances ranging from 1 inch to 100 feet. The reader captures the data from the tag and sends them over a network to a host computer for processing.

HOW RFID WORKS


Radio Frequency Identification

• RFID tags are tiny and need little power• Objects are embedded with tags that contain a transponder (a radio transceiver activated by a signal transmitted to it)

• Tags are encoded with electronic product code• Readers decode data stored in tag’s memory and pass the data to a host computer

• Efficient for large companies, but expensive for smaller companies

What is the Internet?

Internet Addressing and ArchitectureThe Domain Name System

Hierarchical structureTop‐level domains

Internet Architecture and GovernanceNo formal management: IAB, ICANN, W3C

The Future Internet: IPv6 and Internet2

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Network Addresses

• Hostname A unique identification that specifies a particular computer on the InternetFor example

matisse.csc.villanova.educondor.develocorp.com

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Network Addresses

• Network software translates a hostname into its corresponding IP addressFor example

205.39.145.18

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Network Addresses

• An IP address can be split into– Network address, which specifies a specific network– Host number, which specifies a particular machine in that network

An IP address is stored in four bytes

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Domain Name System(DNS)

• A hostname consists of the computer name followed by the domain name

• csc.villanova.edu is the domain name– A domain name is separated into two or more sections that specify the organization, and possibly a subset of an organization, of which the computer is a part

– Two organizations can have a computer named the same thing because the domain name makes it clear which one is being referred to

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Domain Name System

• The very last section of the domain is called its top‐level domain (TLD) name

Figure 15.10 Top-level domains, including some relatively new ones

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Domain Name System

• Organizations based in countries other than the United States use a top‐level domain that corresponds to their two‐letter country codes

Some of the top-level domain names based on country codes

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Domain Name System

• The domain name system (DNS) is chiefly used to translate hostnames into numeric IP addresses

– DNS is an example of a distributed database

– If that server can resolve the hostname, it does so

– If not, that server asks another domain name server

FTP server

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Firewalls, Security

• Firewall A machine and its software that serve as a special gateway to a network, protecting it from inappropriate access

– Filters the network traffic that comes in, checking the validity of the messages as much as possible and perhaps denying some messages altogether

– Enforces an organization’s access control policy

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Firewalls

Figure 15.8 A firewall protecting a LAN

Domain Name System is a hierarchical system with a root domain, top‐level domains, second‐level domains, and host computers at the third level.

THE DOMAIN NAME SYSTEM

TheGlobalInternet

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Internet Connections

• Internet backbone A set of high‐speed networks that carry Internet trafficThese networks are provided by companies such as AT&T, GTE, and IBM

• Internet service provider (ISP) A company that provides other companies or individuals with access to the Internet

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• There are various technologies available that you can use to connect a home computer to the Internet

– A phone modem converts computer data into an analog audio signal for transfer over a telephone line, and then a modem at the destination converts it back again into data

– A digital subscriber line (DSL) uses regular copper phone lines to transfer digital data to and from the phone company’s central office

– A cable modem uses the same line that your cable TV signals come in on to transfer the data back and forth

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• Broadband A connection in which transfer speeds are faster than 128 bits per second– DSL connections and cable modems are broadband connections

– The speed for downloads (getting data from the Internet to your home computer) may not be the same as uploads(sending data from your home computer to the Internet)


TCP/IP

• TCP/IP (Transmission Control Protocol/ Internet Protocol): a set of related protocols– TCP ensures packets arrive accurately and in proper order

– IP ensures efficient delivery of packets from node to node

• Internet backbone: highest speed channels• Host: a computer connected directly to a backbone

• IP number: unique numerical identification for a network device


TCP/IP (continued)

• DNS (Domain Name Service): associates a character‐based name with an IP address

• Static IP address: a permanent address assigned to a device

• Dynamic IP address: temporary IP number assigned to a device for the duration of the connection– Provides flexibility when the number of IP addresses is limited

THE TRANSMISSION CONTROL PROTOCOL/ INTERNET PROTOCOL(TCP/IP) REFERENCE MODEL

The four layers of the TCP/IP reference model for communications

The Internet backbone connects to regional networks, which in turn provide access to Internet service providers, large firms, and government institutions. Network access points (NAPs) and metropolitan area exchanges (MAEs) are hubs where the backbone intersects regional and local networks and where backbone owners connect with one another.

INTERNET NETWORKARCHITECTURE

TheGlobalInternet

Data Via Packet Switching

• To improve the efficiency of transferring information over a shared communication line, messages are divided into fixed‐sized, numbered packets

• Network devices called routers are used to direct packets between networks

Messages sent by packet switching

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Key networking technologies (cont.)

Packet switching

Method of slicing digital messages into parcels (packets), sending packets along different communication paths as they become available, and then reassembling packets at destination

Packet switching more efficient use of network’s communications capacity

PACKED‐SWITCHED NETWORKS AND PACKET COMMUNICATIONS

Data are grouped into small packets, which are transmitted independently over various communications channels and reassembled at their final destination.

circuit‐switched networks required assembly of complete point‐to‐point circuit in the Network

Circuit‐Switched Networks

THE BATTLE OVER NET NEUTRALITY

What is network neutrality? Why has the Internet operated under net neutrality up to this point in time?Who’s in favor of net neutrality? Who’s opposed? Why?What would be the impact on individual users, businesses, and government if Internet providers switched to a tiered service model?Are you in favor of legislation enforcing network neutrality? Why or why not?

Internet services

E‐mailChatting and instant messagingNewsgroupsTelnetFile Transfer Protocol (FTP)World Wide WebVoIPVirtual private network (VPN)

Client computers running Web browser and other software can access an array of services on servers over the Internet. These services may all run on a single server or on multiple specialized servers.

CLIENT/SERVER COMPUTING ON THE INTERNET

An VoIP phone call digitizes and breaks up a voice message into data packets that may

An VoIP phone call digitizes and breaks up a voice message into data packets that may travel along different routes before being reassembled at the final destination.

HOW VOICE OVER IP (VoIP)WORKS

This VPN is a private network of computers linked using a secure “tunnel” connection over the Internet.

It protects data transmitted over the public Internet by encoding the data and “wrapping” them within the Internet Protocol (IP).

A VIRTUAL PRIVATE NETWORK USING THE INTERNET

Should managers monitor employee e‐mail and Internet usage? Why or why not?Describe an effective e‐mail and Web use policy for a company.Should managers inform employees that their Web behavior is being monitored? Or should managers monitor secretly? Why or why not?

MONITORING EMPLOYEES ON NETWORKS: UNETHICAL OR GOOD BUSINESS?

The World Wide Web(WWW,W3)

HTML (Hypertext Markup Language): Formats documents for display on Web

Hypertext Transfer Protocol (HTTP):Communications standard used for transferring Web pages

Uniform resource locators (URLs): Addresses of Web pages

E.g. http://www.megacorp.com/content/features/082602.html

Web serversSoftware for locating and managing Web pages

The World Wide Web (cont.)

Search engines

Started in early 1990s as relatively simple software programs using keyword indexes

Today, major source of Internet advertising revenue via search engine marketing, using complex algorithms and page ranking techniques to locate results

Shopping bots

Use intelligent agent software for searching Internet for shopping information

The Google search engine is continuously crawling the Web, indexing the content of each page, calculating its popularity,

and storing the pages so that it can respond quickly to user requests to see a page.

The entire process takes about one‐half second.

HOW GOOGLE WORKS

Web 2.0

Four defining features1. Interactivity2. Real‐time user control3. Social participation4. User‐generated content

Technologies and services behind these featuresCloud computingBlogs/RSSMashups & widgetsWikisSocial networks

Evolving Web

Web 3.0 − the Seman c Web

Effort of W3C(World Wide Web Consortium) to add meaning to existing WebMake searching more relevant to userSome intelligent Agents are Introduces

Other visionsMore “intelligent” computing3D WebPervasive WebIncrease in cloud computing, SaaSUbiquitous connectivity between mobile and

other access devices

Cellular, Mobile Systems

Competing standards for cellular serviceCDMA: United StatesGSM: Rest of world, plus AT&T and T‐Mobile

Third‐generation (3G) networksSuitable for broadband Internet access 144 Kbps – 2Mbps

4G networksEntirely packet‐switched100 Mbps – 1Gbps

Wireless computer networks and Internet access

Bluetooth (802.15) Links up to 8 devices in 10‐m areaUseful for personal networking (PANs) and in business to transmit data from handheld devices to other transmitters

Wi‐Fi (802.11)Set of standards: 802.11a, 802.11b, 802.11g, 802.11nUsed for wireless LAN and wireless Internet accessUse access points: Device with radio receiver/transmitter for connecting wireless devices to a wired LAN

Bluetooth enables a variety of devices, including cell phones, PDAs, wireless keyboards and mice, PCs, and printers, to interact wirelessly with each other within a small 30‐foot (10‐meter) area. In addition to the links shown, Bluetooth can be used to network similar devices to send data from one PC to another, for example.

A BLUETOOTH NETWORK (PAN)

TheWirelessRevolution

Mobile laptop computers equipped with network interface cards link to the wired LAN by communicating with the access point. The access point uses radio waves to transmit network signals from the wired network to the client adapters, which convert them into data that the mobile device can understand. The client adapter then transmits the data from the mobile device back to the access point, which forwards the data to the wired network.

AN 802.11 WIRELESS LANTheWirelessRevolution

Wireless computer networks and Internet accessWi‐Fi (cont.)

Hotspots: Access points in public place to provide maximum wireless coverage for a specific areaWeak security features

A range of 250–1000 feet (75‐300 meters)

WiMax (802.16)Require WiMax antennasSprint Nextel building WiMax network as foundation for 4G networksWireless access range of 31 miles


Converging Technologies• Convergence occurs in networking technology• Cell phones can act as Web phones using VoIP• Television sets will connect to Internet, cable, and satellites concurrently

• PDAs function as televisions sets and phones• Portable music/video players will communicate with PCs to download files and transmit to wireless earphones

• Cell phones will read RFID on products to compare prices and make purchases

•Telecommunications and Networking in today’s Business WorldNetworking and Communication TrendsWhat is a Computer Network?Key Digital Networking Technologies

•Communications NetworksSignals Digital VS. AnalogTypes of NetworksPhysical Transmission Media

•The Global InternetWhat is the Internet?Internet Addressing and ArchitectureInternet Services and Communication Tools

•The Wireless RevolutionCellular SystemsWireless computer Networks and internet AccessRIFID and Wireless Sensor Networks

Cloud Computing

Modified from Mark Baker

History of Computing

What is Cloud Computing?• Cloud Computing is a general term used to describe a new

class of network based computing that takes place over the Internet, – basically a step on from Utility Computing– a collection/group of integrated and networked hardware, software and Internet infrastructure (called a platform).

– Using the Internet for communication and transport provides hardware, software and networking services to clients

• These platforms hide the complexity and details of the underlying infrastructure from users and applications by providing very simple graphical interface or API (Applications Programming Interface).

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What is Cloud Computing?

• In addition, the platform provides on demand services, that are always on, anywhere, anytime and any place.

• Pay for use and as needed, elastic– scale up and down in capacity and functionalities

• The hardware and software services are available to– general public, enterprises, corporations and businesses markets

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Cloud Summary• Cloud computing is an umbrella term used to refer to Internet based development and services

• A number of characteristics define cloud data, applications services and infrastructure:– Remotely hosted: Services or data are hosted on remote infrastructure.

– Ubiquitous: Services or data are available from anywhere.– Commodified: The result is a utility computing model similar to traditional that of traditional utilities, like gas and electricity ‐ you pay for what you would want!

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Cloud Architecture

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What is Cloud Computing

122 Adopted from: Effectively and Securely Using the Cloud Computing Paradigm by peter Mell, Tim Grance

• Shared pool of configurable computing resources• On‐demand network access• Provisioned by the Service Provider

Cloud Computing Characteristics

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Common Characteristics:

Low Cost Software

Virtualization Service Orientation

Advanced Security

Homogeneity

Massive Scale Resilient Computing

Geographic Distribution

Essential Characteristics:

Resource PoolingBroad Network Access Rapid Elasticity

Measured Service

On Demand Self-Service

Adopted from: Effectively and Securely Using the Cloud Computing Paradigm by peter Mell, Tim Grance

Cloud Service Models

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Software as a Service (SaaS)

Platform as a Service (PaaS)

Infrastructure as a Service (IaaS)

Google App Engine

SalesForce CRM

LotusLive

Adopted from: Effectively and Securely Using the Cloud Computing Paradigm by peter Mell, Tim Grance

SaaS Maturity Model

126 Source: Frederick Chong and Gianpaolo Carraro, “Architectures Strategies for Catching the Long Tail”

Level 2: Configurable per customer

Level 3: configurable & Multi‐Tenant‐Efficient

Level 1: Ad‐Hoc/Custom –One Instance per customer

Level 4: Scalable, Configurable & Multi‐Tenant‐Efficient

Different Cloud Computing Layers

Application Service(SaaS)

Application Platform

Server Platform

Storage Platform Amazon S3, Dell, Apple, ...

3Tera, EC2, SliceHost, GoGrid, RightScale, Linode

Google App Engine, Mosso,Force.com, Engine Yard,Facebook, Heroku, AWS

MS Live/ExchangeLabs, IBM, Google Apps; Salesforce.comQuicken Online, Zoho, Cisco

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Services

Application

Development

Platform

Storage

Hosting

Cloud Computing Service LayersDescriptionServices – Complete business services such as PayPal, OpenID, OAuth, Google Maps, Alexa

Services

ApplicationFocused

InfrastructureFocused

Application – Cloud based software that eliminates the need for local installation such as Google Apps, Microsoft Online

Storage – Data storage or cloud based NAS such as CTERA, iDisk, CloudNAS

Development – Software development platforms used to build custom cloud based applications (PAAS & SAAS) such as SalesForce

Platform – Cloud based platforms, typically provided using virtualization, such as Amazon ECC, Sun Grid

Hosting – Physical data centers such as those run by IBM, HP, NaviSite, etc.

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Basic Cloud Characteristics• The “no‐need‐to‐know” in terms of the underlying details of infrastructure, applications interface with the infrastructure via the APIs.

• The “flexibility and elasticity” allows these systems to scale up and down at will– utilising the resources of all kinds

• CPU, storage, server capacity, load balancing, and databases

• The “pay as much as used and needed” type of utility computing and the “always on!, anywhere and any place” type of network‐based computing.

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Basic Cloud Characteristics

• Cloud are transparent to users and applications, they can be built in multiple ways – branded products, proprietary open source, hardware or software, or just off‐the‐shelf PCs.

• In general, they are built on clusters of PC servers and off‐the‐shelf components plus Open Source software combined with in‐house applications and/or system software.

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Software as a Service (SaaS)• SaaS is a model of software deployment where an application is hosted as a service provided to customers across the Internet.

• Saas alleviates the burden of software maintenance/support– but users relinquish control over software versions and requirements.

• Terms that are used in this sphere include – Platform as a Service (PaaS) and – Infrastructure as a Service (IaaS)

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Virtualization• Virtual workspaces:

– An abstraction of an execution environment that can be made dynamically available to authorized clients by using well‐defined protocols,

– Resource quota (e.g. CPU, memory share),– Software configuration (e.g. O/S, provided services).

• Implement on Virtual Machines (VMs): – Abstraction of a physical host machine,– Hypervisor intercepts and emulates instructions from VMs, and allows

management of VMs,– VMWare, Xen, etc.

• Provide infrastructure API:– Plug‐ins to hardware/support structures

Hardware

OS

App App App

Hypervisor

OS OS

Virtualized StackAn application programming interface (API) is a specification intended to be used as an interface by software components to communicate with each other

Virtual Machines

• VM technology allows multiple virtual machines to run on a single physical machine.

Hardware

Virtual Machine Monitor (VMM) / Hypervisor

Guest OS(Linux)

Guest OS(NetBSD)

Guest OS(Windows)

VM VM VM

AppApp AppAppAppXen

VMWare

UML

Denali

etc.

Performance: Para‐virtualization (e.g. Xen) is very close to raw physical performance!

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Virtualization in General• Advantages of virtual machines:

– Run operating systems where the physical hardware is unavailable,

– Easier to create new machines, backup machines, etc.,– Software testing using “clean” installs of operating systems and software,

– Emulate more machines than are physically available,– Timeshare lightly loaded systems on one host,– Debug problems (suspend and resume the problem machine),– Easy migration of virtual machines (shutdown needed or not).– Run legacy systems!

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What is the purpose and benefits?

• Cloud computing enables companies and applications, which are system infrastructure dependent, to be infrastructure‐less.

• By using the Cloud infrastructure on “pay as used and on demand”, all of us can save in capital and operational investment!

• Clients can:– Put their data on the platform instead of on their own desktop PCs and/or on their own servers.

– They can put their applications on the cloud and use the servers within the cloud to do processing and data manipulations etc.

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Cloud‐Sourcing• Why is it becoming a Big Deal:

– Using high‐scale/low‐cost providers,– Any time/place access via web browser,– Rapid scalability; incremental cost and load sharing,– Can forget need to focus on local IT.

• Concerns:– Performance, reliability, and SLAs,– Control of data, and service parameters,– Application features and choices,– Interaction between Cloud providers,– No standard API – mix of SOAP and REST!– Privacy, security, compliance, trust…

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Some Commercial Cloud Offerings

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Cloud Storage• Several large Web companies are now exploiting the fact that they have data storage capacity that can be hired out to others. – allows data stored remotely to be temporarily cached on desktop computers, mobile phones or other Internet‐linked devices.

• Amazon’s Elastic Compute Cloud (EC2) and Simple Storage Solution (S3) are well known examples– Mechanical Turk

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Amazon Simple Storage Service (S3)

• Unlimited Storage.• Pay for what you use:

– $0.20 per GByte of data transferred,– $0.15 per GByte‐Month for storage used,– Second Life Update:

• 1TBytes, 40,000 downloads in 24 hours ‐ $200,

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Utility Computing – EC2• Amazon Elastic Compute Cloud (EC2):

– Elastic, marshal 1 to 100+ PCs via WS,– Machine Specs…,– Fairly cheap!

• Powered by Xen – a Virtual Machine:– Different from Vmware and VPC as uses “para‐virtualization” where

the guest OS is modified to use special hyper‐calls:– Hardware contributions by Intel (VT‐x/Vanderpool) and AMD (AMD‐V).– Supports “Live Migration” of a virtual machine between hosts.

• Linux, Windows, OpenSolaris• Management Console/AP

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EC2 – The Basics

• Load your image onto S3 and register it.• Boot your image from the Web Service.• Open up required ports for your image.• Connect to your image through SSH.• Execute you application…

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Opportunities and Challenges• The use of the cloud provides a number of opportunities: – It enables services to be used without any understanding of their infrastructure.

– Cloud computing works using economies of scale:• It potentially lowers the outlay expense for start up companies, as they would no longer need to buy their own software or servers.

• Cost would be by on‐demand pricing. • Vendors and Service providers claim costs by establishing an ongoing revenue stream.

– Data and services are stored remotely but accessible from “anywhere”.

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Opportunities and Challenges• In parallel there has been backlash against cloud computing:

– Use of cloud computing means dependence on others and that could possibly limit flexibility and innovation:

• The others are likely become the bigger Internet companies like Google and IBM, who may monopolise the market.

• Some argue that this use of supercomputers is a return to the time of mainframe computing that the PC was a reaction against.

– Security could prove to be a big issue:• It is still unclear how safe out‐sourced data is and when using these services ownership of data is not always clear.

– There are also issues relating to policy and access: • If your data is stored abroad whose policy do you adhere to? • What happens if the remote server goes down? • How will you then access files? • There have been cases of users being locked out of accounts and losing access to data.

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Advantages of Cloud Computing

• Lower computer costs: – You do not need a high‐powered and high‐priced computer to run cloud computing's web‐based applications.

– Since applications run in the cloud, not on the desktop PC, your desktop PC does not need the processing power or hard disk space demanded by traditional desktop software.

– When you are using web‐based applications, your PC can be less expensive, with a smaller hard disk, less memory, more efficient processor...

– In fact, your PC in this scenario does not even need a CD or DVD drive, as no software programs have to be loaded and no document files need to be saved.

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• Improved performance:– With few large programs hogging your computer's memory, you will see better performance from your PC.

– Computers in a cloud computing system boot and run faster because they have fewer programs and processes loaded into memory…

• Reduced software costs: – Instead of purchasing expensive software applications, you can get most of what you need for free‐ish!

• most cloud computing applications today, such as the Google Docs suite.

– better than paying for similar commercial software• which alone may be justification for switching to cloud applications.

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• Instant software updates:– Another advantage to cloud computing is that you are no longer faced

with choosing between obsolete software and high upgrade costs.– When the application is web‐based, updates happen automatically

• available the next time you log into the cloud.

– When you access a web‐based application, you get the latest version • without needing to pay for or download an upgrade.

• Improved document format compatibility. – You do not have to worry about the documents you create on your

machine being compatible with other users' applications or OSes– There are potentially no format incompatibilities when everyone is

sharing documents and applications in the cloud.

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Advantages of Cloud Computing• Unlimited storage capacity:

– Cloud computing offers virtually limitless storage. – Your computer's current 1 Tbyte hard drive is small compared to the hundreds of Pbytes available in the cloud.

• Increased data reliability:– Unlike desktop computing, in which if a hard disk crashes and destroy all your valuable data, a computer crashing in the cloud should not affect the storage of your data.

• if your personal computer crashes, all your data is still out there in the cloud, still accessible

– In a world where few individual desktop PC users back up their data on a regular basis, cloud computing is a data‐safe computing platform!

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• Universal document access:– That is not a problem with cloud computing, because you do not take your documents with you.

– Instead, they stay in the cloud, and you can access them whenever you have a computer and an Internet connection

– Documents are instantly available from wherever you are• Latest version availability:

– When you edit a document at home, that edited version is what you see when you access the document at work.

– The cloud always hosts the latest version of your documents• as long as you are connected, you are not in danger of having an outdated version

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• Easier group collaboration:– Sharing documents leads directly to better collaboration.– Many users do this as it is an important advantages of cloud computing

• multiple users can collaborate easily on documents and projects

• Device independence. – You are no longer tethered to a single computer or network. – Changes to computers, applications and documents follow you through the cloud.

– Move to a portable device, and your applications and documents are still available.

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Disadvantages of Cloud Computing

• Requires a constant Internet connection:– Cloud computing is impossible if you cannot connect to the Internet.

– Since you use the Internet to connect to both your applications and documents, if you do not have an Internet connection you cannot access anything, even your own documents.

– A dead Internet connection means no work and in areas where Internet connections are few or inherently unreliable, this could be a deal‐breaker.

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• Does not work well with low‐speed connections: – Similarly, a low‐speed Internet connection, such as that found with dial‐up services, makes cloud computing painful at best and often impossible.

– Web‐based applications require a lot of bandwidth to download, as do large documents.

• Features might be limited:– This situation is bound to change, but today many web‐based applications simply are not as full‐featured as their desktop‐based applications.

• For example, you can do a lot more with Microsoft PowerPoint than with Google Presentation's web‐based offering

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• Can be slow:– Even with a fast connection, web‐based applications can sometimes be slower than accessing a similar software program on your desktop PC.

– Everything about the program, from the interface to the current document, has to be sent back and forth from your computer to the computers in the cloud.

– If the cloud servers happen to be backed up at that moment, or if the Internet is having a slow day, you would not get the instantaneous access you might expect from desktop applications.

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• Stored data might not be secure:– With cloud computing, all your data is stored on the cloud.

• The questions is How secure is the cloud?

– Can unauthorised users gain access to your confidential data?

• Stored data can be lost:– Theoretically, data stored in the cloud is safe, replicated across multiple machines.

– But on the off chance that your data goes missing, you have no physical or local backup.

• Put simply, relying on the cloud puts you at risk if the cloud lets you down.

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• HPC(High Performance Computer) Systems:– Not clear that you can run compute‐intensive HPC applications that use MPI/OpenMP!

– Scheduling is important with this type of application• as you want all the VM to be co‐located to minimize communication latency!

• General Concerns:– Each cloud systems uses different protocols and different APIs

• may not be possible to run applications between cloud based systems– Amazon has created its own DB system (not SQL 92), and workflow system (many popular workflow systems out there)

• so your normal applications will have to be adapted to execute on these platforms.

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The Future• Many of the activities loosely grouped together under cloud

computing have already been happening and centralised computing activity is not a new phenomena

• Grid Computing was the last research‐led centralised approach

• However there are concerns that the mainstream adoption of cloud computing could cause many problems for users

• Many new open source systems appearing that you can install and run on your local cluster– should be able to run a variety of applications on these systems

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What is the cloud?

• IT as a service

• Cloud allows access to services without user technical knowledge or control of supporting infrastructure

• Best described in terms of what happened to mechanical power over 100 yrs ago

• Now computers are simple devices connected to the larger cloud

• Data processing, storage and software applications that used to run locally are now being supplied by big central computing stations. They're becoming, in essence, computing utilities.

What isCloud Computing?

Summary

SaaSSoftware as a Service

PaaSPlatform as a Service

IaaSInfrastructure as a Service

Software delivery model

• Increasingly popular with SMEs• No hardware or software to manage

• Service delivered through a browser

SaaS

Advantages

• Pay per use• Instant Scalability• Security• Reliability• APIs

SaaS

Examples• CRM• Financial Planning• Human Resources• Word processing

Commercial Services:• Salesforce.com• emailcloud

SaaS

Platform delivery model

• Platforms are built upon Infrastructure, which is expensive

• Estimating demand is not a science!

• Platform management is not fun!

PaaS

Popular services

• Storage• Database• Scalability

PaaS

Advantages


PaaS

Examples

• Google App Engine• Mosso• AWS: S3

PaaS

Computer infrastructure delivery model

Access to infrastructure stack:– Full OS access– Firewalls– Routers– Load balancing

IaaS

Advantages

• Pay per use• Instant Scalability• Security• Reliability• APIsIaaS

Examples

• Flexiscale• AWS: EC2

IaaS

Common Factors


IaaS

PaaS

SaaS

Advantages

• Lower cost of ownership• Reduce infrastructure management responsibility

• Allow for unexpected resource loads

• Faster application rolloutIaaS

PaaS

SaaS

Cloud Economics

• Multi‐tenented• Virtualisation lowers costs by increasing utilisation

• Economies of scale afforded by technology

• Automated update policyIaaS

PaaS

SaaS

Risks

• Security• Downtime• Access• Dependency• InteroperabilityIaaS

PaaS

SaaS

Questions?