Transcript Lecture 1 Title: MIS Concept and Definition

Lecture 5
Title: Networks and Businesses
By: Mr Hashem Alaidaros
MIS 101
Main Points
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Components for large networks
IP addresses
VoIP
Intranet vs. Extranet vs. Internet
VPN
Cloud Computing: Models
Web 2 & Web 3
Large Networks
• Networks in large companies
• Components can include:
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Hundreds of local area networks (LANs) linked to firmwide corporate network
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Various powerful servers
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Web site
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Corporate intranet, extranet
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Backend systems
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Mobile wireless LANs (Wi-Fi networks)
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Videoconferencing system
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Telephone network ( handle voice data)
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Wireless cell phones
Telecommunications and Networking in Today’s Business World
Corporate Network Infrastructure
IP address
 IP address: is an address that identify each computer that
connected to a network (or Internet)
 Example of IP address: 52.55.14.7
 IP address types:
 Private (local)
 Public (global)
 IP address and Port number
Cont.
• The Future Internet (IPv4 to IPv6)
• The IP addresses currently in use, such as
208.55.112.34 are part of a specification called
IPv4.
• However, given the growth rate of the Internet,
there aren’t enough IP addresses in this scheme to
last beyond 2013.
• IPv6 is a revised addressing convention that will
provide over a quadrillion addresses
The Domain Name System
Figure 7-8
The Domain Name System is a
hierarchical system with a root
domain, top-level domains, secondlevel domains, and host computers at
the third level.
Internet Connection
• What is the Internet?
• Connecting to the Internet
• Internet service providers (ISPs)
• Services
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DSL, cable, satellite, T lines (T1, T3)
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T lines (or leased lines) are leased, dedicated lines
suitable for businesses or government agencies
requiring high-speed guaranteed service levels.
Internet Services
• Internet services
• E-mail
• Chatting and instant messaging
• Newsgroups
• File Transfer Protocol (FTP)
• World Wide Web
• Voice over IP (VoIP)
• Virtual private networks (VPNs)
Client/Server Computing on the Internet
Figure 7-10
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.
VoIP
• What is VoIP?
• 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.
• A processor nearest the call’s destination, called a gateway,
arranges the packets in the proper order and directs them to
the telephone number of the receiver or the IP address of the
receiving computer.
• Skype, acquired by eBay, offers free VoIP worldwide using a
peer-to-peer network.
The Internet
How Voice over IP Works
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. A processor nearest the call’s destination, called a gateway, arranges the packets in the proper order and directs them to
the telephone number of the receiver or the IP address of the receiving computer.
Figure 7-11
Web Terms
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The World Wide Web
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Hypertext Markup Language (HTML): Formats documents for
display on Web
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Hypertext Transfer Protocol (HTTP): Communications standard
used for transferring Web pages
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Uniform resource locators (URLs): Addresses of Web pages
E.g., http://www.megacorp.com/content/features/082602.html
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Web servers: Software for locating and managing Web pages
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Firewall: a device that sits between an internal network and the
Internet, limiting access into and out of a network based on access
policies
Intranet
• Intranets
• They are web pages or resources in a network that is
not available to the world outside of the Intranet.
• Used only be insider employees to gain access to
corporate information
• The firewall helps to control access between the
Intranet and Internet to permit access to the Intranet
only to people who are members of the same
company or organization.
• It is accessed is via a username and password
Extranet
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Extranets
• An Extranet is actually an Intranet that is partially accessible to
authorized outsiders. The actual server (the computer that
serves up the web pages) will reside behind a firewall.
• Allow authorized vendors and customers access to an internal
intranet
• Example: Used
for collaboration between companies and
suppliers.
• Example: VPN
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The purpose for both Intranets and Extranets are communication
tools for easy information sharing within groups.
IntErnet
 Internet
 It is used when users access a web server (website)
that doesn’t reside behind a firewall (if it reside behind
a firewall, it would be an Extranet).
 All the information is accessible.
 Important Question: What are the
benefits and the Problems of
Intranet and Extranet?
How VPN works
 A VPN is used to allow access to certain resources on a
network from outside.
 When you want to connect to a restricted company
resources (files or data) from outside the company:
you connect to your Internet Service Provider (ISP)
2. then activate a VPN client program on your computer.
3. The client program then communicates with a VPN
server at the company and then verifies your username
password (by firewall),
4. a secure encrypted link is established and you can
access the resources you need.
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VPN
Cloud Computing
 Cloud
Computing is the
use of computing
resources
(hardware
and
software) that are
delivered as a
service over the
Interne.
Cloud Computing Models
 Service as a service (SAAS) allows users to run online
applications. Off-the-shelf applications are accessed over the
Internet. The vendors own the applications and the users pay a fixed
subscription fees. Great for generic applications, but not for
customized, complex applications for large enterprises.
 Platform as a service (PAAS) allows users to create their own cloud
applications. Basically, provides an environment and set of tools to
allow the creation of new web applications. More risk of vendor lockin because applications cannot be moved easily between platforms.
 Infrastructure as a service (IAAS) allows users to run any
applications they want to on cloud hardware of their choice. Existing
applications can be run on the vendor’s cloud hardware, potentially
replacing a company’s data center infrastructure.
Web 2.0
• Web 2.0:
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Second-generation interactive Internet-based services
enabling people to collaborate, share information, and
create new services online
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Blogs: Chronological, informal Web sites created by
individuals using easy-to-use weblog publishing tools
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RSS (Really Simple Syndication): Syndicates Web content
so aggregator software can pull content for use in another
setting or viewing later
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Wikis: Collaborative Web sites where visitors can add,
delete, or modify content on the site
Web 3.0
• Web 3.0
• Current efforts to make using Web more productive
Inefficiency of current search engines: Of 330 million
search engine queries daily, how many are fruitful?
Semantic Web
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Collaborative effort to add layer of meaning on top of
Web, to reduce the amount of human involvement in
searching for and processing Web information
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