Transcript Chapter 2 The Intranet and Extranets

Chapter 2
The Intranet and Extranets
1
The Internet
The Internet is a public and global
communication network that provides
direct connectivity to anyone via a
Local Area Network (LAN) and an
Internet Service provider (ISP).
Access to the Internet is not restricted
to anyone. There is no centralized
control of network and information.
2
The Intranets
An intranet is a corporate LAN and/or Wide Area
Network (WAN) that is secured behind
company’s firewalls and it uses Internet
technologies. Although intranets are developed
using the same TCP/IP protocol as the Internet,
they operate as private networks with limited
access. Intranets are limited to information
pertinent to the company and contain exclusive
and often proprietary and sensitive information.
Firewalls protect intranets from unauthorized
outside access.
3
The Intranet (cont.)
Servers
ERP
Clients
Legacy
systems
Public/External
Internet Users
Intranet
E-mail
servers
Web
servers
Firewalls
Databases
4
The Extranet
An extranet implies an “extended intranet”, which
uses TCP/IP protocol networks (like the Internet) to
link intranets in different locations. Extranet
transmissions are conducted over the Internet to
save money. But it offers no privacy or transmission
security. By creating tunnels of secure data flows
using cryptography and authorization algorithms,
called VPNs, the security can be improved.
Extranets provide secure connectivity between a
corporation’s intranets and intranets of its business
partners, material suppliers, financial services, and
customers.
5
The Extranet (cont.)
Extranet
Suppliers
Intranet
VPN
Distributors
VPN
Firewall
Tunneling Internet
Intranet
VPN
Customers
Firewall
6
Summary : Internet, Intranet, and Extranet
Network
Type
Internet
Typical
Users
Any individual
with dial-up
access or LAN
Type of
Access
Unlimited,
public; no
restrictions
Intranet
Authorized
employees
ONLY
Authorized
groups from
collaborating
companies
Private and
restricted
Extranet
Private and
outside
authorized
partners
Information
General, public
and advertisement
Specific,
corporate and
proprietary
Shared in
authorized
collaborating
group
7
Firewalls
Definition of Firewall
Software and hardware that allows only those
external users with specific characteristics to
access a protected network
Provides potential customers with secured
account, credit card, and loan information
Usually located at a gateway point and controls
traffic between internal and external networks
8
Generic Functions of an Intranet
 Corporate/department/individual Web-pages
 Database access: Web-based databases
 Search engines and directory: Assist key word-based search
 Interactive communication: Chatting, audio and videoconferencing
 Document distribution and workflow: Web-based download and
routing of documents
 Groupware: Enhanced e-mail and a bulletin board
 Telephony: Intranets are the perfect conduit for computer-based
telephony
 Integration with electronic commerce: Interface with Internetbased electronic sales and purchasing
 Extranet: Link geographically dispersed branches, customers and
suppliers to authorize sections of Internets. Can create happier
customers, more efficient suppliers, and reduce operating costs
9
Elements of Extranets
Components of Extranets
Tunneling technology
Intranets
Interface software
Web server
Business application
Firewalls
Internet Service Provider (ISP)
Methods to Configure Extranets
They can be implemented using a direct leased
line with full control over it, linking all intranets
A secure link can be created across the Internet,
which can be used by the corporation as a
virtually private network (VPN)
10
Virtually Private Network (VPN)
 VPN is a secure network on the Internet using the
tunneling schemes
 The major objective of a VPN is to use the Internet
as an inexpensive WAN backbone
 When two sites are connected across a VPN, each
must have a VPN-capable router, firewall, or VPN
access device installed
 When VPN is used to link mobile clients with
Internet dial-up connections, the laptops must be
equipped with VPN client software equipped with
the addresses and associated encryption keys for
corporate host sites
11
Four Categories of Extranet
Products and Services
Extranet development tools
Extranet hosting and network
connectivity
Extranet services
VPNs
12
Categories of Extranet Application
Enhanced Communications
Productivity Enhancements
Business Enhancements
Cost Reduction
Information Delivery
13