Unit 7 - Internet and Intranet Applications - IT

Internet and Intranet
Applications
Unit 7
By
Deep Raj Bhujel

Email:
Fig: Operation Overview

Message Format:
• The Internet email message format is now defined with multi-media
content attachments collectively called Multipurpose Internet Mail
Extensions or MIME.
• Internet email messages consist of two major sections:
Header – Structured into fields such as From, To, CC, Subject, Date, and other
information about the email.
Body – The basic content, as unstructured text; sometimes contains
a signature block at the end. This is exactly the same as the body of a regular
letter.
• The header is separated from the body by a blank line.

Types:
• Web-Based Email (Webmail):
• POP3 Email Services:
• IMAP Email Servers:
• MAPI Email Servers:

Multipurpose Internet Mail Extensions (MIME):
• It is an Internet standard that extends the format of email to support:
Text in character sets other than ASCII
Non-text attachments
Message bodies with multiple parts
Header information in non-ASCII character sets
• The basic Internet email transmission protocol, SMTP, supports only 7-
bit ASCII characters.
• MIME defines mechanisms for sending other kinds of information in email. These
include text in languages other than English using character encodings other than
ASCII, and 8-bit binary content such as files containing images, sounds, movies,
and computer programs.
• Mapping messages into and out of MIME format is typically done automatically
by an email client or by mail servers when sending or receiving Internet
(SMTP/MIME) email.

Gopher:
• The Gopher protocol is a TCP/IP application layer protocol designed for
distributing, searching, and retrieving documents over the Internet.
• Strongly oriented towards a menu-document design, the Gopher protocol
presented an attractive alternative to the World Wide Web in its early
stages, but ultimately failed to achieve popularity.
• Gopher uses a server-client protocol to access and manage the files.
• Gopher clients use the TCP port 70 to connect to the Gopher servers.
• The server sends a list of files available, with each line having a standard
code that identifies the type of file. It uses 0 for files, 1 for directories and 7
for search services.

• Its central goals were,
A file-like hierarchical arrangement that would be familiar to
users.
A simple syntax.
A system that can be created quickly and inexpensively.
Extending the file system metaphor, such as searches.

Multimedia and Digital Video/Audio Broadcasting:
• Digital Video Broadcasting (DVB)
• Digital Audio Broadcasting (DAB)

Internet Relay Chat (IRC):
• IRC is a method to broadcast and receive live, synchronous,
messages.
• It is a protocol for real-time Internet text messaging (chat)
or synchronous conferencing.
• It is mainly designed for group communication in discussion forums,
called channels, but also allows one-to-one
communication via private message as well as chat and data
transfer, including file sharing.

Components of IRC:
• Servers:
• Clients:
• User Clients:
• Service Clients:
Architecture of IRC:
• An IRC network is defined by a group of servers connected to each other. A single server
forms the simplest IRC network.
• The only network configuration allowed for IRC servers is that of a spanning tree where
each server acts as a central node for the rest of the network it sees.
• The IRC protocol provides no mean for two clients to directly communicate. All
communication between clients is relayed by the server(s).

IRC Protocol Services:
• Client Locator: To be able to exchange messages, two clients must be able to
locate each other. Upon connecting to a server, a client registers using a label
which is then used by other servers and clients to know where the client is
located. Servers are responsible for keeping track of all the labels being used.
• Message Relaying: The IRC protocol provides no mean for two clients to directly
communicate. All communication between clients is relayed by the server(s).
• Channel Hosting and Management: A channel is a named group of one or more
users which will all receive messages addressed to that channel. A channel is
characterized by its name and current members, it also has a set of properties
which can be manipulated by (some of) its members. Channels provide a mean
for a message to be sent to several clients. Servers host channels, providing the
necessary message multiplexing. Servers are also responsible for managing
channels by keeping track of the channel members. The exact role of servers is
defined in "Internet Relay Chat: Channel Management".

Broadband Communication:
• The term broadband refers to a telecommunications signal or device
of greater bandwidth, in some sense, than another standard or usual
signal or device (and the broader the band, the greater the capacity
for traffic).
DSL
ADSL
SDSL
Cable Internet
VOIP:
GSM VOIP (GOIP)
IP Interconnection

DSL
Benefits
• High-speed data service: DSL typically >10x faster
than 56-kbps analog modem
• Always on connection: No need to “dial-up”
• Uses existing copper wires: Co-exists w/ POTS
service
• Reasonably priced today and getting cheaper
Applications
• High speed Internet access
• Multimedia, Long distance learning, gaming
• Video on Demand
• VPN
• VoDSL
Q. ADSL Vs. SDSL

Cable Internet
• Broadband cable Internet access requires a cable modem at the customer's
premises and a cable modem termination system at a cable operator facility,
typically a cable television head-end.
• The two are connected via coaxial cable or a Hybrid Fiber Coaxial (HFC) plant.
• The distance between the modem and the termination system is up to 100 miles
(160 km).
• Downstream: 400Mbit/s for business connections, and 100Mbit/s for residential
service in some countries.
• Upstream traffic, originating at the user, ranges from 384kbit/s to more than
20Mbit/s.
• One downstream channel can handle hundreds of cable modems. As the system
grows, the cable modem termination system (CMTS) can be upgraded with more
downstream and upstream ports, and grouped into hubs CMTS for efficient
management.

VOIP
• VOIP commonly refers to the communication protocols, technologies, methodologies, and
transmission techniques involved in the delivery of voice
communications and multimedia sessions over Internet Protocol (IP) networks, such as
the Internet.
• Other terms commonly associated with VoIP are IP telephony, Internet telephony, voice over
broadband (VoBB), broadband telephony, IP communications, and broadband phone.
• Internet telephony refers to communications services — voice, fax, SMS, and/or voice-messaging
applications— that are transported via the Internet, rather than the public switched telephone
network (PSTN).
• The steps involved in originating a VoIP telephone call are signaling and media channel setup,
digitization of the analog voice signal, encoding, packetization, and transmission as Internet
Protocol (IP) packets over a packet-switched network.
• On the receiving side, similar steps (usually in the reverse order) such as reception of the IP
packets, decoding of the packets and digital-to-analog conversion reproduce the original voice
stream.
• E.g. Skype, Google Talk etc.

Examples of the network protocols used to implement VoIP include:
• H.323
• Media Gateway Control Protocol (MGCP)
• Session Initiation Protocol (SIP)
• Real-time Transport Protocol (RTP)
• Session Description Protocol (SDP)

IP Interconnection
• Interconnection links networks so as to enable the customers of one
operator to establish and maintain communications with the customers of
another operator.
• The majority of connections between two IP-based networks today take
place according to one of two basic interconnection models: transit and
peering.
• Transit is an inherently asymmetric model. The transit provider (the ISP)
carries traffic for the transit customer, but the transit customer is not under
any obligation to carry traffic for the transit provider. The transit customer
pays the provider, not the other way around.
• With peering, ISPs exchange traffic for their respective customers (and for
customers of their respective customers), but not for third parties. Peering
is a substantially symmetric form of network interconnection.

Unit 7 - Internet and Intranet Applications - IT

Data Centers:
• A data center or computer centre (also datacenter) is a facility used
to house computer systems and associated components, such as
telecommunications and storage systems.
• It generally includes redundant or backup power supplies, redundant
data communications connections, environmental controls (e.g., air
conditioning, fire suppression) and security devices.

Three main elements of datacenters consist of:
1. hardware (servers, switches, routers, modems, and network
utilities),
2. utilities required for environmental controls (including temperature
control, humidity, Closed Circuit Cameras, and fire alarms),
3. Information security (such as using hardware and software and
security procedures and the appropriate network design for this
purpose to materialize)

Presently, the companies and the organizations use one of the three
following methods to save their information and applications:
• Use foreign datacenter services
• Keep servers within their organizations
• Use domestic datacenter services

In general, data centers can be broken down into three types-
• An Internet Data Center (IDC) is a facility that provides data and
Internet services for other companies
• A Storage Area Network (SAN) is a network of interconnected storage
devices and data servers usually located within an enterprise data
center or as an off-site facility offering leased storage space.
• An Enterprise Data Center (EDC) is the central processing facility for
an enterprise’s computer network

Data Warehousing:
• Data warehousing is the process of constructing and using a data
warehouse.
• A data warehouse is constructed by integrating data from multiple
heterogeneous sources that support analytical reporting, structured
and/or ad hoc queries, and decision making.

Packet Clearing House:
• Packet Clearing House is a non-profit research institute that supports
operations and analysis in the areas of Internet traffic exchange,
routing economics, and global network development.
• It has since grown to become a leading proponent of neutral
independent network interconnection and provider of route-servers
at major exchange points worldwide.
• PCH provides equipment, training, data, and operational support to
organizations and individual researchers seeking to improve the
quality, robustness, and accessibility of the Internet.

Unified Messaging:
• Unified Messaging is the integration of different
electronic messaging and communications media (e-
mail, SMS, Fax, voicemail, video messaging, etc.) technologies into a single
interface, accessible from a variety of different devices.
• While traditional communications systems delivered messages into several
different types of stores such as voicemail systems, e-mail servers, and
stand-alone fax machines, with Unified Messaging all types of messages
are stored in one system.
• Voicemail messages, for example, can be delivered directly into the user's
inbox and played either through a headset or the computer's speaker.
• This simplifies the user's experience (only one place to check for messages)
and can offer new options for workflow such as appending notes or
documents to forwarded voicemails.

Benefits of Unified Messaging
• A single inbox. Unified messaging can deliver all types of messaging and communication
to a single inbox. The single inbox is easier for administrators to maintain, and provides
flexibility for users to manage and interact with all of their communications.
• Efficient communication. Users can communicate more efficiently by having access to all
communications at one time and being free to share, forward, or manage them in the
way that's most convenient or effective for the given communication.
• Cost savings. Merging streamlines the communications administration and consolidates
the infrastructure onto fewer physical servers, saving money for the enterprise.
• Access from anywhere. Unified messaging provides alternative methods of accessing
communications. By merging e-mail, voice, and other communications, users can get
voice messages in e-mail, have e-mail dictated over the phone, or access
communications via the Web.

E-commerce:
• Traditional commerce:
Mass-marketing and sales force-driven
Difficulty to search for the best price and quality
Information asymmetry – any disparity in relevant market information among
parties in transaction
• E-commerce:
In its broadest definition, e-commerce is digitally enabled commercial
transactions between and among organizations and individuals, where
digitally enabled means, for the most part, transactions that occur over the
Internet and World Wide Web.

Ecommerce can be defined from different dimensions as;
• From a communications perspective, EC is the delivery of information, product/services,
or payments over telephone lines, computer networks, or any other electronic means.
• From a business process perspective, EC is the application of technology toward the
automation of business transactions and work flow.
• From a service perspective, EC is a tool that addresses the desire of firms, consumers,
and management to cut service costs while improving the quality of goods and
increasing the speed of service delivery.
• From an online perspective, EC provides the capability of buying and selling products
and information on the Internet and other online services.
• From a collaboration perspective, EC is the facilitator for inter- and intra-organizational
collaboration.
• From a community perspective, EC provides place for community members, to learn,
transact and collaborate.

E-commerce Vs. E-business:
• E-business is the use of Internet and digital technology to execute all
the business processes in the enterprise. E-business includes e-
commerce as well as processes for the internal management of the
firm and for coordination with suppliers and other business partners.
E-business includes digital enabling of transactions and processes
within a firm, involving information systems under the control of the
firm.
• For example, a company’s online inventory control mechanisms are a
component of e-business and online selling of company product is e-
commerce.

Types of e-commerce:
Classified by the nature of market relationship – who is selling to whom
• Business-to-Consumer (B2C)
 Businesses sell products or services to individual customers
 Example: Walmart.com sells merchandise to consumers through its Web site
• Business-to-Business (B2B)
 Businesses sell products or services to other businesses
 Types include inter-business exchanges, e-distributors, B2B service providers, matchmakers and
infomediaries.
 Examples: Grainger.com sells industrial supplies to large and small businesses through its Web site, Intel sells
products to other business rather than customers.
• Consumer-to-Consumer (C2C)
 Participants in an online marketplace can buy and sell goods with each other
 Example: Consumers and businesses trade with each other on eBay.com

Classified by technology used:
• Peer-to-Peer (P2P)
Use of peer-to-peer technology, which enables Internet users to share files
and computer resources directly without having to go through a central Web
server, in e-commerce
Examples: BitTorrent and eDonkey.
• Mobile commerce (M-commerce)
Use of digital wireless devices to enable transactions on the Web

Unique features of e-commerce
The features the set e-commerce Technology apart from others used in traditional
commerce are:
• Ubiquity – internet/web technology is available everywhere: at work, home and
elsewhere via mobile devices.
Marketplace extended beyond traditional boundaries
“Marketspace” is created, available 24/7/365
Customer convenience increased, costs reduced.
Ubiquity reduces transaction cost – the cost of participating in a market
• Global Reach – the technology reaches across national boundaries, around the
learth.
The potential market size is roughly equal to the size of the world’s online population
The total number of users or customers an e-commerce business can obtain is a measure of
its reach.

• Universal standards – there is one set of technology standards, namely
internet standards that is shared by all nations around the world.
Promotes technology adoption
Reduces costs of adoption
Greatly lower market entry cost for merchants
Reduce search cost for consumers
• Richness – Refers to the complexity and content of a message
Video, audio, and text messages are integrated into a single marketing message
The Internet has the potential for offering considerably more information richness
than traditional media like printing press, radio, and television because it is
interactive and can adjust the message to individual users

• Information Density – Internet and Web vastly increase the total amount
and quality of information available to all market participants
Information processing, storage and communication costs drop dramatically.
Accuracy and timeliness improve greatly.
Information becomes plentiful, cheap and accurate.
• Interactivity – the technology allows active user involvement.
Enable two-way communication between merchant and consumer
Traditional televisions cannot ask viewers any questions or enter into conversations,
and it cannot request that customer information be entered into a form
Interactivity allows an online merchant to engage a consumer in ways similar to a
face-to-face experience on a global scale where consumers engage in dynamic dialog

• Social Technology – the technology allows the persons to create communities of
their own interest.
The Internet and e-commerce technologies have evolved to be much more social by allowing
users to create and share content in the form of text, videos, music, or photos with a
worldwide community.
Using these forms of communication, users are able to create new social networks and
strengthen existing ones
• Personalization/Customization – the technology reaches allows personalized
messages to be delivered to individuals as well as groups.
E-commerce technologies permit personalization by targeting of marketing message to
specific individuals by adjusting the message to a person’s name, interests, and past
purchases
The technology also permits by changing the delivered product or service based on user’s
preferences or prior behavior
Potential customer reach extended.

E-commerce Challenges:
Although using e-commerce offers organization a wealth of new
opportunities and ways of doing business, it also presents managers with a
number of serious challenges as given below
• Unproven Business Models - Many Internet business models are new and
largely unproven to prove enduring sources of profit
• Business Process Change Requirements - Web-enabled business processes
for e-commerce and e-business requires far-reaching organizational change
• Channel Conflicts - Using the Web for online sales and marketing may
create channel conflicts with the firm’s traditional channels
• Legal Issues - laws governing electronic commerce are still being written
• Trust, Security, and Privacy - Electronic commerce does not provide trust
among buyers, sellers, and other partners involved in online transactions.

Grid Computing:
• Grid computing is a computer network in which each computer's
resources are shared with every other computer in the system.
• Processing power, memory and data storage are all community
resources that authorized users can tap into and leverage for specific
tasks.
• A grid computing system can be as simple as a collection of similar
computers running on the same operating system or as complex as
inter-networked systems comprised of every computer platform you
can think of.

Cloud Computing:
• Cloud computing is the use of computing resources (hardware and
software) that are delivered as a service over a network (typically
the Internet).
• The name comes from the use of a cloud-shaped symbol as an
abstraction for the complex infrastructure it contains in system
diagrams.
• Cloud computing entrusts remote services with a user's data,
software and computation.

Characteristics:
• Agility improves with users' ability to re-provision technological
infrastructure resources.
• Application programming interface (API) accessibility to software that
enables machines to interact with cloud software in the same way the user
interface facilitates interaction between humans and computers.
• Cost is claimed to be reduced and in a public cloud delivery model capital
expenditure is converted to operational expenditure. This is purported to
lower barriers to entry, as infrastructure is typically provided by a third-
party and does not need to be purchased for one-time or infrequent
intensive computing tasks. Pricing on a utility computing basis is fine-
grained with usage-based options and fewer IT skills are required for
implementation (in-house)

• Device and location independence enable users to access systems using a web
browser regardless of their location or what device they are using (e.g., PC,
mobile phone). As infrastructure is off-site (typically provided by a third-party)
and accessed via the Internet, users can connect from anywhere.
• Virtualization technology allows servers and storage devices to be shared and
utilization be increased. Applications can be easily migrated from one physical
server to another.
• Multitenancy enables sharing of resources and costs across a large pool of users
thus allowing for:
Centralization of infrastructure in locations with lower costs (such as real estate, electricity,
etc.)
Peak-load capacity increases (users need not engineer for highest possible load-levels)
Utilisation and efficiency

• Reliability is improved if multiple redundant sites are used, which makes well-
designed cloud computing suitable for business continuity and disaster recovery.
• Scalability and elasticity via dynamic ("on-demand") provisioning of resources on
a fine-grained, self-service basis near real-time, without users having to engineer
for peak loads.
• Performance is monitored, and consistent and loosely coupled architectures are
constructed using web services as the system interface.
• Security could improve due to centralization of data, increased security-focused
resources, etc., but concerns can persist about loss of control over certain
sensitive data, and the lack of security for stored kernels.
• Maintenance of cloud computing applications is easier, because they do not need
to be installed on each user's computer and can be accessed from different
places.

Cloud Service Models:
• Cloud computing providers offer
their services according to three
fundamental models:
1. Infrastructure as a Service
(IaaS)
2. Platform as a Service (PaaS)
3. Software as a Service (SaaS)
• IaaS is the most basic and each
higher model abstracts from the
details of the lower models.

Unit 7 - Internet and Intranet Applications - IT

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Unit 7 - Internet and Intranet Applications - IT