Infrastructure for ECInfrastructure for ECChapter 11Chapter 11

A network of networksA network of networks ISPs ISPs

– A commercial organization with a A commercial organization with a permanent connection to the Internet that permanent connection to the Internet that sells temporary connections to subscribers sells temporary connections to subscribers

NSPsNSPs– Network that spans a large geographical Network that spans a large geographical

distance. May consist of a variety of cable, distance. May consist of a variety of cable, satellite, and microwave technologies. satellite, and microwave technologies. example PTCL example PTCL

Internet Protocols Internet Protocols Protocol :A set of rules and procedures that govern Protocol :A set of rules and procedures that govern

transmission between the components in a network transmission between the components in a network – InteroperableInteroperable– LayeredLayered– SimpleSimple– End to EndEnd to End

TCP/IPTCP/IP– Transmission Control Protocol/Internet Protocol (TCP/IP) Transmission Control Protocol/Internet Protocol (TCP/IP)

Leading model for achieving connectivity among Leading model for achieving connectivity among different networks. Provides a universally agree-on different networks. Provides a universally agree-on method for breaking up digital messages into packets, method for breaking up digital messages into packets, routing them to the proper addresses, and then routing them to the proper addresses, and then reassembling them into coherent messages.reassembling them into coherent messages.

TCP/IP architecture TCP/IP architecture – Transmission Control ProtocolTransmission Control Protocol– Internet Protocol (IP) address Four-part numeric address Internet Protocol (IP) address Four-part numeric address

indicating a unique computer location on the Internetindicating a unique computer location on the Internet– 130.211.100.105130.211.100.105

Domain names: English-like name that corresponds to Domain names: English-like name that corresponds to the unique 32-bit numeric Internet Protocol (IP) address the unique 32-bit numeric Internet Protocol (IP) address for each computer connected to the Internet. for each computer connected to the Internet.

Client / server applicationsClient / server applications– Client software: An easy-to-use software tool for accessing Client software: An easy-to-use software tool for accessing

the World Wide Web and the Internet. the World Wide Web and the Internet. – Server software :Software that manages requests for Web Server software :Software that manages requests for Web

pages on the computer where they are stored and that pages on the computer where they are stored and that delivers the page to the user's computer. delivers the page to the user's computer.

WWW2WWW2– Internet2 Research network with new protocols and Internet2 Research network with new protocols and

transmission speeds that provides an infrastructure for transmission speeds that provides an infrastructure for supporting high-bandwidth Internet applications.supporting high-bandwidth Internet applications.

– Second-generation, interactive Internet-based services that Second-generation, interactive Internet-based services that enable people to collaborate, share information, and create enable people to collaborate, share information, and create new services online, including mashups, blogs, and wikis. new services online, including mashups, blogs, and wikis.

web-based client web-based client serverserver Hypertext transfer protocol (HTTP)Hypertext transfer protocol (HTTP)

– The communications standard used to transfer The communications standard used to transfer pages on the Web. Defines how messages are pages on the Web. Defines how messages are formatted and transmitted. (P423)formatted and transmitted. (P423)

URLs: Uniform Resource Locator ,The URLs: Uniform Resource Locator ,The address of a specific resource on the address of a specific resource on the Internet.Internet.

Web browsersWeb browsers Web serversWeb servers

Internet Security Internet Security

SecuritySecurity– Policies, procedures, and technical measures used to prevent Policies, procedures, and technical measures used to prevent

unauthorized access, alteration, theft, or physical damage to unauthorized access, alteration, theft, or physical damage to information systems.information systems.

security policy:security policy:– Statements ranking information risks, identifying acceptable Statements ranking information risks, identifying acceptable

security goals, and identifying the mechanisms for achieving these security goals, and identifying the mechanisms for achieving these goals.goals.

Corner stones of securityCorner stones of security– AuthenticityAuthenticity– PrivacyPrivacy– IntegrityIntegrity– Non repudiationNon repudiation

VPNVPN– Virtual Private Network (VPN)A secure connection between two Virtual Private Network (VPN)A secure connection between two

points across the Internet to transmit corporate data. Provides a low-points across the Internet to transmit corporate data. Provides a low-cost alternative to a private networkcost alternative to a private network

Selling on the netSelling on the net Functional Requirements (437)Functional Requirements (437) OutsourcingOutsourcing

OutsourcingOutsourcing OutsourcingOutsourcing is when an organization acquires IT is when an organization acquires IT

applications or services from outside contractors or applications or services from outside contractors or external organizations.external organizations.– Outsourcing is the practice of contracting computer Outsourcing is the practice of contracting computer

center operations, telecommunications networks, or center operations, telecommunications networks, or applications development to external vendors.applications development to external vendors.

Offshore software outsourcing: Outsourcing systems Offshore software outsourcing: Outsourcing systems development work or maintenance of existing systems development work or maintenance of existing systems to external vendors in another country.to external vendors in another country.

Application service provider (ASP)Application service provider (ASP) is an agent or is an agent or vendor who assembles the software needed by vendor who assembles the software needed by enterprises and packages the software with services enterprises and packages the software with services such as development, operations and maintenance.such as development, operations and maintenance.– ASPASP manages application servers from a centrally manages application servers from a centrally

controlled location rather than at a customer’s site.controlled location rather than at a customer’s site.

In-sourcingIn-sourcing IN-HOUSE DEVELOPMENT APPROACHES. There are two IN-HOUSE DEVELOPMENT APPROACHES. There are two

major approaches to in-house development: building major approaches to in-house development: building from scratch or building from components.from scratch or building from components.– Build from scratch. This option should be considered only Build from scratch. This option should be considered only

for specialized applications for which components are not for specialized applications for which components are not available. It is an expensive and slow process, but it will available. It is an expensive and slow process, but it will provide the best fit.provide the best fit.

– Build from components. Companies with experienced IT Build from components. Companies with experienced IT staff can use standard components (e.g., a secure Web staff can use standard components (e.g., a secure Web server), some software languages (e.g., Java, Visual Basic, server), some software languages (e.g., Java, Visual Basic, or Perl), and third-party subroutines to create and or Perl), and third-party subroutines to create and maintain applications on their own. (Or, companies can maintain applications on their own. (Or, companies can outsource the entire development process to an outsource the entire development process to an integrator that assembles the components.) From a integrator that assembles the components.) From a software standpoint, using components offers the software standpoint, using components offers the greatest flexibility and can be the least expensive option greatest flexibility and can be the least expensive option in the long run. However, it can also result in a number of in the long run. However, it can also result in a number of false starts and wasted experimentations. For this reason, false starts and wasted experimentations. For this reason, even those companies with experienced staff are even those companies with experienced staff are frequently better off modifying and customizing one of frequently better off modifying and customizing one of the packaged solutions as part of the “buy” option.the packaged solutions as part of the “buy” option.

Chatting on the webChatting on the web– Communication centersCommunication centers– Customer serviceCustomer service– Community discussionCommunity discussion

Multimedia DeliveryMultimedia Delivery– Web castingWeb casting

Publishing audio/video broadcasts via the Internet so that Publishing audio/video broadcasts via the Internet so that subscribing users can download audio/video files onto subscribing users can download audio/video files onto their personal computers or portable players. their personal computers or portable players.

– Bandwidth requirementsBandwidth requirements Bandwidth:The capacity of a communications channel as Bandwidth:The capacity of a communications channel as

measured by the difference between the highest and measured by the difference between the highest and lowest frequencies that can be transmitted by that lowest frequencies that can be transmitted by that channel.channel.

Analyzing the web visitsAnalyzing the web visits