Transcript Chapter 42 - Personal Web Pages

ITIS 1210
Introduction to Web-Based
Information Systems
Chapter 42
How Intranets Work
Introduction
 An intranet is a private corporate network
 Used for
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Email
Group meetings/videoconferencing
Scheduling
Access to corporate databases & documents
Sales of goods and services
Introduction
 Use same technologies as rest of Internet
 TCP/IP
 WWW
 FTP
 Difference is that these resources are not
available to the public at large
 Usually protected behind a firewall
 HW/SW that prohibits unauthorized access
Introduction
 Users on the inside can access the
Internet
 However, outside users are prohibited
Using an Intranet Within a Company
 Firewall controls access
 Employees inside firewall
 Rest of world outside
 Some outsiders permitted entry
 Key component is a email server
 Works like regular Internet email
 Typically routes within organization
 However, can access Internet through firewall
Using an Intranet Within a Company
 Corporate database may contain
 Data
 Financial information
 Research
 Documents
 Software documentation
 Project information
 Plans
 Corporate vision
 Sales strategies
Using an Intranet Within a Company
 Corporate databases may provide access
 HTML documents
 Search tools
 Groupware enables collaboration
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Online meetings
Scheduling
Work on documents
Any kind of cooperative work
Using an Intranet Within a Company
 Videoconferencing
 Enables meetings when participants are
physically separated
 Within Intranet high speed is more possible
 Corporation controls
 More difficult working within constraints of regular
Internet
Using an Intranet Within a Company
 Security can be built into the firewall
 Makes it easier to do business with
subcontractors and other businesses
 Secure Web link to
 Submit bids
 Send invoices
 Receive electronic payments
Using an Intranet Within a Company
 Customers can buy goods and services
 Browse through company catalogs
 Using company’s public Web site
 Order goods
 Submit payments
 Transactions travel through the firewall
 In both directions
 Encryption provides security
How VPNs Work
 A Virtual Private Network (VPN) lets
groups create their own private network
 Without the actual expense
 Corporations can use one so their
employees can connect to the company
intranet wherever they are in the world
 In example, a remote PC user
communicates to an employee back at
headquarters
How VPNs Work
 The remote PC runs VPN client software
 The message is encrypted using the
recipient’s public key
 (Book is wrong)
 Encrypted message packets encapsulated
inside a normal IP packet
 The destination address is that of a PC or
router at the other end of a tunnel
How VPNs Work
 True destination address cannot be read
by snoopers, only tunnel address
 Packets travel across the Internet as usual
 Routers read tunnel address and move the
packets closer to their destination
 At destination end of tunnel the IP packet
is stripped off
How VPNs Work
 The inner packet is decrypted
 This reveals the true destination address
 The packets are delivered to the recipient