E-COMMERCE OE SEM 5 UNIT II

 UNIT-II- Internet: Concept & evaluation, Features of Internet: email, WWW, ftp, telnet, newsgroup & video conferencing; Intranet & Extranet, ISDN, TCP/IP, Limitation of internet, Hardware & software requirement of Internet.

Internet: Concept & Evaluation

The first workable prototype of the Internet came in the late 1960s. ARPANET (Advanced Research Projects Agency Network). Originally funded by the U.S. Department of Defense, ARPANET used packet switching to allow multiple computers to communicate on a single network. The technology continued to grow in the 1970s after scientists Robert Kahn and Vinton Cerf developed Transmission Control Protocol and Internet Protocol, or TCP/IP, a communications model that set standards for how data could be transmitted between multiple networks. ARPANET adopted TCP/IP on January 1, 1983, and from there researchers began to assemble the “network of networks” that became the modern Internet. The online world then took on a more recognizable form in 1990, when computer scientist Tim Berners-Lee invented the World Wide Web. While it’s often confused with the Internet itself, the web is actually just the most common means of accessing data online in the form of websites and hyperlinks.

The Internet, World Wide Web (WWW) and information super highway have penetrated into lives of millions of people all over the world. The Internet is a network made up of thousands of networks worldwide. Obviously, these networks are composed of computers and other intelligent and active devices. In fact, Internet is an example of self-regulating mechanism and there is no one in-charge of the Internet.

There are organizations which are entrusted to develop technical aspects of this network, but no governing body is in control. Private companies own the Internet backbone, through which Internet traffic or data flows in the form of text, video, graphics, sound image etc. All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol architecture, abbreviated to TCP/IP, based on client/server architecture. This means that the remote server machine provides files and services to the user' local client machine. Software can be installed or a client computer to take advantage of the latest access technology.

A wide variety of services, namely, electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, and many more are available on the Internet. To provide all these services, the Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.

Transmission Control Protocol/Internet Protocol (TCPIP) is the protocol suite developed for the Internet.

History of the Internet

The Internet, www and Information Super Highway are terms which have deep impact in the lives of millions of people all over the world. The widespread impact of Internet across the globe could not be possible without the development of Transmission Control Protocol/Internet Protocol (TCP/IP). This is the protocol suite developed specifically for the Internet. The Information Technology revolution of today cannot be achieved without this vast network of networks. This has become a fundamental part of life of millions of people all over the world. All the aforesaid services, basically, provide us the necessary backbone for information sharing in organizations and within common interest groups. That information may be in several forms. It can be notes and documents, data to be processed by another computer, files sent to colleagues, and even more exotic forms of data

During late 1960s and 1970s, organizations were inundated with many different LAN and WAN technologies such as packet switching technology, collision-detection local area networks, hierarchical enterprise networks, and many other excellent technologies. The major drawbacks with all these technologies were that they could not communicate to each other without expensive deployment of communication devices. These were not only expensive but also put users at the mercy of the monopoly of the vendor they would be dealing with. Consequently, multiple networking models were available as a result of the research and development efforts made by many interest groups. This paved (make it easier) the way for development of another aspect of networking known as protocol layering. This allows applications to communicate with each other. A complete range of architectural models was proposed and implemented by various research teams and computer manufacturers. The result of all this great know-how is that today, any group of users can find a physical network and an architectural model suitable for their specific needs. This includes cheap asynchronous lines with no other error recovery than a bit-per-bit parity function, through full-function wide area networks (public or private) with reliable protocols such as public packet switching networks or private SNA (Systems Network Architecture) networks, to high-speed but limited-distance local area networks.

This is now evident that organizations or users are using different network technology to connect computer over the network. The desire of sharing more and more information among homogeneous or heterogeneous interest group motivated the researcher to devise the technology so that one group of users may extend its information system to another group of users who happen to have a different network technology and different network protocols. This necessity was recognized in the beginning of the 1970s by a group of researchers in the United States of America who hit upon a new principle popularly known as internetworking. Other organizations also became involved in this area of interconnecting networks, such as ITU-T(International Telecommunications Union – Telecommunications Sector)(formerly CCITI (Consultative Committee on Information Technology Industry)) and ISO(International Organization for Standardization). All were trying to define a set of protocols, layered in a well-defined suite, so that applications would be able to communicate to other applications, regardless of the underlying network technology and the operating systems where those applications run.

Features of Internet:

1.     The World Wide Web.

2.     E-mail.

3.     News

4.     Telnet

5.     File Transfer Protocol (FTP)

6.     Internet Relay Chat (IRC)

7.     Newsgroup & video conferencing

8.     Intranet & Extranet

9.                                                            ISDN (Integrated Services Digital Network)

10.               TCP/IP (Transmission Control Protocol/Internet Protocol,)

11.               Limitation of internet

12.               Hardware & software requirement of Internet.

The World Wide Web

• The World Wide Web is a part of the internet, which supports hypertext documents, allowing users to view and navigate different types of data.
• A web page is a document encoded with hypertext markup language (HTML) tags.
• HTML allows designers to link content together via hyperlinks.
• Every web page has an address, a uniform resource locator (URL).

E-mail

• Electronic mail (e-mail) is the most popular reason people use the Internet.
• To create, send, and receive e-mail messages you need an e-mail program and an account on an Internet mail server with a domain name.
• To use e-mail, a user must have an e-mail address, which you create by adding your user name to the e-mail create by adding your user name to the e-mail server’s domain name, as in jsmith@aol.com.

News

• One Internet based service called news, includes tens of thousands of newsgroups.
• Each newsgroup hosts discussions on a specific topic. A newsgroups a some indicated its users special topic of interest, such as alt. food. cake.
• To participate in a newsgroup, you need a news-reader program hat.left you read articles that have been posted on a news server. You can post articles for others to read and respond to.

Telnet

• Telnet is a specialized service that lets you use one computer to access the contents of another computer a telnet host.
• A telnet program creates a “Window” into the host so you can access files, issue commands, and exchange data.
• Telnet is widely used by libraries to allow visitors to look up information, find articles and so on.

File transfer protocol

• File Transfer protocol (FTP) is the internet tool used to copy files from one computer to another.
• Using a special FTP program or a web browser, you can log into an ETP host Computer over the internet and copy files on to your computer.
• FTP is handy for finding and copying software files, articles and other types of data. Universities and software companies use FTP servers to provide visitors with access to data.

Internet Relay chat (IRC)

• Internet Relay chat (IRC) is a service that allows users to communicate in real time by typing text in a special window.
• Like news, there are hundreds of IRC “channel” each devoted to a subject or user group.
• You can use a special IRC program to participate in chat room discussions but many chat rooms are set up in web sites, enabling visitors to chat directly in their browser window.

Internet Communication Tools

There are many different forms of communications that rely on the Internet, including e-mail, instant messaging, blogs, newsgroups and discussion forums. Newsgroups and discussion forums differ from other forms of communication by allowing you to post to a large number of potential users and by archiving the postings over time.

Newsgroups

A newsgroup is a repository of electronic messages posted by users and managed by the Usenet system. This is a worldwide Internet discussion system that is separate from the World Wide Web. Usenet was established in 1980, a little more than 10 years before the creation of the World Wide Web. Newsgroups on Usenet were one of the first opportunities for general computer users to share and post information on the emerging Internet.

Participants in a newsgroup read and post messages to one or more categories. Usenet was created in a time when the bandwidth of the Internet was very limited, and newsgroups were designed to be text only. More recently, users were able to attach images and other files to postings, but in general, newsgroups remain very heavily text-based.

Originally, newsgroups required special software known as newsreader software. This software somewhat resembles an e-mail system, but messages are not sent to a single individual. Messages are posted to newsgroups, which look like folders in newsreader software. When a user connects to a particular newsgroup, all the messages posted to this newsgroup are downloaded to the newsreader software.

The communication protocol used by newsgroups is called Network News Transfer Protocol, or NNTP. This is one of the many communication protocols used on the Internet, which also includes the more well-known HTTP protocol used by the World Wide Web. The name of a newsgroup is determined by those who create it. A name typically consists of two to three words that describe the topic, separated by a dot. Here are some examples of typical names:

Newsgroup Examples

Below are some examples of active newsgroups. The first part of the name (before the first dot) is the primary category (or hierarchy) or the newsgroup. For example, sci. is used for science-related discussions.

Comp

Computer-related topics.

comp.software.testing

Humanities

Topics related to the humanities (fine arts, literature, philosophy, Classical Latin, etc.).

Misc

Miscellaneous topics. Examples include:

·        misc.legal.moderated — A moderated legal forum.

·        misc.taxes.moderated — A moderated professional tax forum open to the general public.

News

Matters related to the functioning of Usenet itself.

· news.admin.net-abuse.blocklisting — discussion related to the use of blocklists to deal with spam and other unwanted network traffic.

· news.admin.net-abuse.email — discussion of abuse of email by spammers and other parties.

rec

Recreation and entertainment topics.

·        rec.arts.movies.current-films—The latest movie releases.

·        rec.arts.movies.past-films—Past films.

·        rec.arts.poems

sci

Science-related topics.

· sci.physics

· Sci.bio.*

o        sci.bio.paleontology

o        sci.bio.evolution

· sci.skeptic

soc

Discussion related to society and social subcultures. Examples include:

· soc.culture.usa— for the discussion of culture in the USA.

· soc.culture.iraq— for the discussion of Iraq.

· soc.art.california

talk

Discussion of various topics, especially controversial ones. Includes political topics as well. Examples include:

·        talk.bizarre — a newsgroup for experiencing the bizarre.

·        talk.origins — evolution-creationism controversy which maintains an extensive FAQ.

·        talk.religion

The alt hierarchy

This is the most extensive newsgroup hierarchy outside of the Big 8. Examples include:

· alt.2600 — Official group for 2600

· Alt.Adoption — for adoption

· alt.arts.poetry.comments — for poetry and poetry critique (a piece of writing that describes the good and bad points of somebody/something)

· alt.asian-movies — for discussions focusing mainly on Hong Kong action cinema.

· alt.politics

· alt.comics.superman

There are thousands of different newsgroups. In newsreader software, each of the groups represents a folder with messages shown in the order that they were posted. At present, you can use an Internet browser to participate in newsgroups. For example, a service like Google Groups integrates a number of different types of online communications, including newsgroups. In addition, many e-mail software applications make it possible to participate in newsgroups in addition to using regular e-mail. However, dedicated newsreader software is often preferred since it provides more options to search and filter postings.

Newsgroups are different from similar communication methods that use the World Wide Web in a number of ways:

• No registration with a particular newsgroup is required
• Stored information is distributed on a collection of computers instead of a central server
• Archives are always available
• Newsreader software is commonly used to read and post messages

In recent years, the popularity of newsgroups has declined substantially as web-based discussion forums, blogs and mailing lists have become more popular. However, newsgroups remain very popular for a number of reasons. First, it is very easy to participate and contribute to newsgroups or even to create your own. Second, the information contained in newsgroups is not located on a central server or controlled by one particular organization or company - for some people, this makes it more of a bottoms-up approach to using the Internet.

 

Video Conferencing

What Is Video Conferencing?

Video conferencing is a technology that allows users in different locations to hold face-to-face meetings without having to move to a single location together. This technology is particularly convenient for business users in different cities or even different countries because it saves time, expense, and hassle associated with business travel. Uses for video conferencing include holding routine meetings, negotiating business deals, and interviewing job candidates.

 

How Video Conferencing Works

Video conferencing main advantage over teleconferencing is that users can see each other, which allows them to develop stronger relationships. When a video conference is held for informal purposes, it is called a video call or video chat.

There are a variety of ways video conferencing can be conducted. Individuals may use web cameras connected to our built into laptop, tablet, or desktop computers. Smartphones equipped with cameras may also be used to connect for video conferences. In such instances, a software-based platform typically is used to transmit the communication over Internet protocols.

[Important: The stability and quality of the video conference may fluctuate with the speed and reliability of the data connection.]

Some businesses use dedicated video conferencing rooms that have been equipped with high-grade cameras and screens to ensure the conversation is clear and with limited technical faults. Third-party providers often install and assemble the hardware needed to conduct the video conference.

 

Uses of Video Conferencing

Companies with multiple offices might establish direct video communications between their locations in order to allow their teams to work more collaboratively.

Video conferencing can also be used as a medium for conducting training, with the instructor teaching a remote class from most anywhere. This can be done in a corporate context, especially for getting workers the knowledge they need to better perform their jobs. The academic world can also make use of video conferencing to connect a traditional classroom setting with students who are based a considerable distance from the school.

A video conference may also be used to conduct regular meetings with a company staff or to confer with shareholders about the latest activities at the business. It may be used to announce significant changes at a company, such as introducing a new CEO or to present information in an interactive way that allows all participants to engage in discussion about what they see on screen.

Hotels and conference centers sometimes make video conferencing services available to guests who require such services. This may be offered in suites or conference rooms that have been equipped for this purpose.

Key Takeaways (a key fact, point, or idea to be remembered)

• Video conferencing is a highly convenient use of technology that allows users in different locations to hold face-to-face meeti
• ngs.
• There are many ways to utilize video conferencing technology, such as company meetings, job training sessions, or addressing board members.
• Video conferencing can be used to connect a traditional classroom with students who are taking the class remotely.
• The stability and quality of the video conference may fluctuate with the speed and reliability of the data connection.
• There are a variety of ways video conferencing can be conducted—like using smartphones and tablets or via desktop computers.

 

 

 

Intranets VS Extranets - What's the difference?

What is the difference between intranet and extranet?

An intranet is a network where employees can create content, communicate, collaborate, get stuff done, and develop the company culture. An extranet is like an intranet, but also provides controlled access to authorized customers, vendors, partners, or others outside the company.

For many, understanding the difference between an intranet and extranet can be confusing – especially for those who have never used them before.

 

Intranets and extranets support two different areas within a business, but have similar goals: to improve how employees work with clients and each other. Sometimes they exist within the same software, other times, separately.

Once integrated into a business model, these portals can make day to day activities more efficient, more streamlined, better connected, and more productive.

But let's not get ahead of ourselves... before you plan on implementing extranet or intranet software, you need to understand how these platforms work, what their features do, and how they will benefit your business. The better you can grasp these concepts, the more likely you'll reap their advantages.

 

What is an intranet?

The prefix intra means within or inside. Therefore, an intranet is the company's digital workspace that centralizes and streamlines every person, document, tool, conversation, and project within your company.

The major difference from an extranet, however, is that an intranet is used internally. While an extranet allows businesses to communicate with clients and vendors, an intranet allows employees and colleagues to work together in a virtual space — no outside parties are involved.

Businesses use intranets for a variety of reasons ... because like extranets, a company intranet streamlines daily activity, organizes people and data, improves internal communications, and increases employee engagement. They also solve many challenges for remote teams and large organizations by connecting staff with colleagues, information, and projects – no matter where they are.

Strong intranet software is packed with features that improve three main areas within your business: communication, collaboration, and connectivity. When you prioritize all three, your staff will work better, smarter, and happier. Let's take a look at how these features work.

 

Benefits of the Intranet

It helps in getting the message across the staff members in the organization. As a result, there are fun activities which can be performed on the intranet as well. Here are some of the benefits of the intranet in the organization.

Productivity

Due to the intranet, the information can be accessed anywhere and at anytime. This helps the workplace get the information whenever they want. Thus, they can view the information faster and use it as per their needs.

Time-saving

It helps people in the organization get information based on their needs. Thus, only the required amount of information is being given to the employees and it takes very less time to process it. The employees may link this information to a relevant one and based on their convenience.

Reduces cost

Anytime the information is needed, employees can access using their desktop or the smartphone. This helps the company in saving the extra space which is required in the form of the physical documents being stored in the organization.

There is various information like the internal phone numbers, procedure materials which are required on a day to day basis. When this information is available on hand, it can essentially save the time as well as the money. The organization is freed from costs like printing, maintenance, and many more.

Communication

Intranet can save time by making the communications quick. It works as a powerful tool for an organization horizontally as well as vertically. It can initiate the strategic communications within the company and as it is secure, companies can rely on it. Every member of the team can be up to date with just a single click.

What is an extranet?

If an intranet is the digital workplace for internal communications, an extranet is the digital platform for external communications.

 

Think of it this way:

"Extra" refers to any contact or activity outside of your business, such as clients, vendors, and suppliers.

Therefore, an extranet is a private network where these individuals (clients, vendors, suppliers, partners, etc.) can communicate with you and your employees in a closed digital workspace. Extranets serve an extremely important role, as they allow for private communication, collaboration, knowledge sharing, document sharing, and data transfer between organizations.

An extranet supports a variety of needs. Large volumes of data can be exchanged between parties via extranets, for example, thus facilitating easy collaboration. These collaboration tools are particularly useful for companies that need to brainstorm or communicate frequently with clients and customers. It saves hours of time in comparison to email and telephone. Extranets also monitor and fix potential bugs or issues that can occur with a company's products or services — almost like built-in quality control.

 

The benefits of implementing an extranet.

There are many reasons why it might be beneficial for your business to implement an extranet.

An extranet can add value to your company by helping you communicate and collaborate more effectively with clients, customers, and partners. Particularly in the business-to-business market, an extranet can give your company an edge over the competition and save you money by streamlining traditional business functions and cutting overhead costs.

Extranets offer small businesses many other advantages:

Increased productivity. As you automate processes that were traditionally done manually, bottlenecks will disappear and your company’s productivity will increase. Critical information won’t get lost in the mail or buried in an e-mail inbox, and busy employees won’t miss or forget key events. An extranet can, for example, monitor business activities and trigger specific actions, such as automatically placing an order with a supplier when your inventory drops below a certain level.

 

Reduced margin of error. An extranet can reduce your margin of error, especially when you use it to give specific groups access to internal applications. This could involve something as simple as giving customers access to their order histories, or something as complex as processing orders from distributors and suppliers.

 

Flexibility. When you use an extranet to make information and applications available to partners, clients, and customers, everyone can operate when and where it’s most convenient. This self-serve approach frees you from unnecessary meetings and phone tag, and it cuts down on the costs associated with in-person information exchanges. For example, an extranet may allow you to provide customer-service information outside of regular business hours.

Timely and accurate information. On an extranet you can instantly change, edit, and update sensitive information such as price lists or inventory information. Compared to typical paper-based publishing processes, an extranet offers a unique opportunity to get hot information into the right hands before it cools — and before it’s out-of-date.

Shorter time to market. If your business is not moving at “Internet speed,” you risk being left behind. An extranet can help you get your products to market more quickly by making proposals and specifications available to suppliers, and giving clients and partners up-to-date information on current projects.

Reduced inventory. One of the hallmarks of a business-to-business extranet is its impact on supply-chain management. By linking your inventory system directly to a supplier, you can process orders as soon as the system knows you need them, thus reducing the stock you keep on hand and making the procurement process more efficient.

Build customer loyalty. Extranets make business easier for your customers. The more you make timely, accurate information available to your customers, the more likely it is you’ll keep their business.

As these examples demonstrate, an extranet can help you spend less on supplies, staffing, and other overhead costs. Given the investment an extranet requires, it may take time for savings to become apparent. Over a period of weeks or months, however, eliminating even one paper-based process can yield dramatic savings.

ISDN - What is the ISDN?

The ISDN technology (Integrated Services Digital Network, or ISDN) means complete digitization so that all communication established in digital form, providing a wide range of services.

Integrated Services Digital Network is a telephone system network. It is a wide area network becoming widely available. Prior to the ISDN, the phone system was viewed as a way to transport voice, with some special services available for data. The key feature of the ISDN is that it integrates speech and data on the same lines, adding features that were not available in the classic telephone system.

 

ISDN is a circuit -switched telephone network system, that also provides access to packet switched networks, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better voice quality than· an analog phone. It offers circuit-switched connections (for either voice or data), and packet-switched connections (for data), in increments of 64 Kbit/s. 

 

Another major market application is Internet access, where ISDN typically provides a maximum of 128 Kbit/s in both upstream and downstream directions (which can be considered to be broadband speed, since it exceeds the narrowband speeds of standard analog 56k telephone lines). ISDN B-channels can be bonded to achieve a greater data rate; typically 3 or 4 BRIs (6 to 8 64 Kbit/s channels) are bonded. 

 

ISDN should not be mistaken for its use with a specific protocol, such as Q.931 whereby ISDN is employed as the network, data-link and physical layers in the context of the OSI model. In a broad sense ISDN can be considered a suite of digital services existing on layers 1, 2 and 3 of the OSI model. ISDN is designed to provide access to voice and data services simultaneously.

 

However, common use has reduced ISDN to be limited to Q.931 and related protocols, which are a set of protocols for establishing and breaking circuit switched connections, and for advanced call features for the user. They were introduced in 1986. In a videoconference, ISDN provides simultaneous voice, video, and text transmission between individual desktop videoconferencing systems and group (room) videoconferencing systems. 

The first generation of ISDN is called as a narrowband ISDN and it is based on the use of 64 kbps channel as the basic unit of switching and has a circuit switching orientation. The main device in the narrowband ISDN is the frame relay. The second generation of ISDN is referred to as the broadband ISDN (B-ISDN).

It supports very high data rates (typically hundreds of Mbps).

 It has a packet switching orientation. The main important technical contribution of B-ISDN is the asynchronous transfer mode (ATM), which is also called as cell relay.

 

ISDN

The ISDN technology (Integrated Services Digital Network). Earlier, the transmission of data and voice both were possible through normal POTS (Plain Old Telephone Systems). With the introduction of Internet came the advancement in telecommunication too. Yet, the sending and receiving of data along with voice was not an easy task. One could use either the Internet or the Telephone. The invention of ISDN helped mitigate this problem.

The process of connecting a home computer to the Internet Service Provider used to take a lot of effort. The usage of the modulator-demodulator unit, simply called the MODEM was the essential thing to establish a connection. The following figure shows how the model worked in the past.

The above figure shows that the digital signals have to be converted into analog and analog signals to digital using modem during the whole path. What if the digital information at one end reaches to the other end in the same mode, without all these connections? It is this basic idea that lead to the development of ISDN.

As the system has to use the telephone cable through the telephone exchange for using the Internet, the usage of telephone for voice calls was not permitted. The introduction of ISDN has resolved this problem allowing the transmission of both voice and data simultaneously. This has many advanced features over the traditional PSTN, Public Switched Telephone Network.

 

ISDN

ISDN was first defined in the CCITT (Consultative Committee for International Telephony and Telegraphy)  red book in 1988.The Integrated Services of Digital Networking, in short ISDN is a telephone network based infrastructure that allows the transmission of voice and data simultaneously at a high speed with greater efficiency. This is a circuit switched telephone network system, which also provides access to Packet switched networks.

 

The model of a practical ISDN is as shown below.

 

The ability to transfer information between the user and ISDN structured in the form of information transfer channels:

• Channel A: It is an analog channel of 4 Khz.
• Channel B: It is a 64 Kbps digital channel that intended for the transport of user information.
• Channel C: It is an 8 or 16 Kbps digital channel.
• Channel D: It is a digital channel of 16 or 64 Kbps intended primarily for the transmission of user-network signaling information for communication control, although it can also use under certain conditions for the transfer of user information in services selection (telealarm, telecontrol, and Telemedia) and low capacity data transmission.
• Channel E: It is a 64 Kbps digital channel (used for internal ISDN signals).
• Channel H: It is a digital channel of 384, 1,536 or 1,920 kbps that provides the user with an information transfer capability.

 

These channels can be combined differently, giving rise to two types of access:
• Basic access.
• Primary access.

 

 

 

Basic access

Basic access, known as 2B + D access, BRA (Basic Rate Access) or BRI (Basic Rate Interface), provides the user with two B channels and a 16 Kbps D channel.

It allows establishing up to two simultaneous communications at 64 Kbps, being able to use the capacity of the D channel for low-speed data transmission.

The main application of this type of access occurs in small local network facilities with a small number of terminals (up to eight) that require digital transmission or small capacity digital exchanges.

 

Primary Access

Primary access, also called 30B + D access, PARA (Primary Rate Access) or PRI (Primary Rate Interface), offers the user 30 B channels and a 64 kbps D channel, thus providing a bandwidth of up to 2,048 Kbps (in the US it consists of 23 B channels and a 64 Kbps D channel, so it provides a bandwidth of up to 1,544 Kbps).

It allows establishing up to thirty simultaneous communications at 64Kbps without currently planning to use the capacity of the D-channel for data transmission. You can also use other combinations of channels B, H0, H11 and H12, but always respecting the speed limit of 2,048 Kbps. The main application of this type of access is the connection to ISDN of small digital exchanges, multi-line systems, and local area networks of medium and large capacity.

 

Types of ISDN Interfaces

Among the types of several interfaces present, some of them contains channels such as the B-Channels or Bearer Channels that are used to transmit voice and data simultaneously; the D- Channels or Delta Channels that are used for signaling purpose to set up communication.

 

The ISDN has several kinds of access interfaces such as −

1.                    Basic Rate Interface (BRI)

2.                    Primary Rate Interface (PRI)

3.                    Narrowband ISDN

4.                    Broadband ISDN

 

Basic Rate Interface (BRI)

The Basic Rate Interface or Basic Rate Access, simply called the ISDN BRI Connection uses the existing telephone infrastructure. The BRI configuration provides two data or bearer channels at 64 Kbits/sec speed and one control or delta channel at 16 Kbits/sec. This is a standard rate.

The ISDN BRI interface is commonly used by smaller organizations or home users or within a local group, limiting a smaller area.

 

Primary Rate Interface (PRI)

The Primary Rate Interface or Primary Rate Access, simply called the ISDN PRI connection is used by enterprises and offices. The PRI configuration is based on T-carrier or T1 in the US, Canada and Japan countries consisting of 23 dataor bearer channels and one control or delta channel, with 64kbps speed for a bandwidth of 1.544 M bits/sec. The PRI configuration is based on E-carrier or E1 in Europe, Australia and few Asian countries consisting of 30 data or bearer channels and two-control or delta channel with 64kbps speed for a bandwidth of 2.048 M bits/sec.

The ISDN BRI interface is used by larger organizations or enterprises and for Internet Service Providers.

 

 

 

Narrowband ISDN

The Narrowband Integrated Services Digital Network is called the N-ISDN. This can be understood as a telecommunication that carries voice information in a narrow band of frequencies. This is actually an attempt to digitize the analog voice information. This uses 64kbps circuit switching.

The narrowband ISDN is implemented to carry voice data, which uses lesser bandwidth, on a limited number of frequencies.

 

Broadband ISDN

The Broadband Integrated Services Digital Network is called the B-ISDN. This integrates the digital networking services and provides digital transmission over ordinary telephone wires, as well as over other media. The CCITT defined it as, “Qualifying a service or system requiring transmission channels capable of supporting rates greater than primary rates.”

 

The broadband ISDN speed is around 2 MBPS to 1 GBPS and the transmission is related to ATM, i.e., Asynchronous Transfer Mode. The broadband ISDN communication is usually made using the fiber optic cables.

As the speed is greater than 1.544 Mbps, the communications based on this are called Broadband Communications. The broadband services provide a continuous flow of information, which is distributed from a central source to an unlimited number of authorized receivers connected to the network. Though a user can access this flow of information, he cannot control it.

 

Principle of ISDN

The ISDN works based on the standards defined by ITU-T (formerly CCITT). (The Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. The standardization work of ITU dates back to 1865, with the birth of the International Telegraph Union. It became a United Nations specialized agency in 1947, and the International Telegraph and Telephone Consultative Committee (CCITT), (from the French name "Comite Consultatif International de Telephonique et Telegraphique") was created in 1956. It was renamed ITU-T in 1993.

 

Principles of ISDN  

The various principles of ISDN as per ITU-T recommendation are:

 

I. To support voice and non-voice applications

The main feature of the ISDN concept is the support of a wide range of voice (for e.g. Telephone calls) & non-voice (for e.g. digital data exchange) applications in the same network.

 

2. to support switched and non-switched applications

ISDN supports both circuit switching and packet switching. In addition ISDN supports non-switched services in the form of dedicated lines.

 

3. Reliance on 64-kbps connections

ISDN provides circuit switched and packet switched connections at 64 kbps. This is the fundamental building block of ISDN. This rate was chosen because at the time, it was standard rate for digitized voice.

 

4. Intelligence in the network

An ISDN is expected to provide sophisticated services beyond the simple setup of circuit switched calls. These services include maintenance and network management functions.

 

5. Layered protocol architecture

A layered protocol structure should be used for the specification of the access to an ISDN. Such a structure can be mapped into OSI model.

 

6. Variety of configurations

Several configurations are possible for implementing ISDN. This allows for differences in national policy, in state of technology and in the needs and existing equipment of the customer base.

 

ISDN Services  

The purpose of the ISDN is to provide fully integrated digital services to users. These services fall into categories- better services, teleservices and supplementary services.

 

1. Bearer Services: Bearer services provide the means to transfer information (voice, data and video) between users without the network manipulating the content of that information. The network does not need to process the information and therefore does not change the content.

Bearer services belong to the first three layers of the OSI model and are well defined in the ISDN standard. They can be provided using circuit-switched, packet-switched, frame-switched, or cell-switched networks.

 

2. Teleservices: In teleservices, the network may change or process the contents of the data. These services correspond to layers 4-7 of the OSI model. Teleservices relay on the facilities of the bearer services and are designed to accommodate complex user needs, without the user having to be aware of the details of the process. Teleservices include telephony, teletex, telefax, videotex, telex and teleconferencing. Although the ISDN defines these services by name, they have not yet become standards.

                        

 

3. Supplementary Service: Supplementary services are those services that provide additional functionality to the bearer services and teleservices. Examples of these services are reverse charging, call waiting, and message handling, all familiar from today's telephone company services.

 

ISDN supports a variety of services. A few of them are listed below −

1.                    Voice calls

2.                    Facsimile

3.                    Videotext

4.                    Teletext

5.                    Electronic Mail

6.                    Database access

7.                    Data transmission and voice

8.                    Connection to internet

9.                    Electronic Fund transfer

10.          Image and graphics exchange

11.          Document storage and transfer

12.          Audio and Video Conferencing

13.          Automatic alarm services to fire stations, police, medical etc.

 

Advantages of ISDN

ISDN is a telephone network based infrastructure, which enables the transmission of both voice and data simultaneously.

There are many advantages of ISDN such as −

As the services are digital, there is less chance for errors.

The connection is faster.

The bandwidth is higher.

Voice, data and video − all of these can be sent over a single ISDN line.

 

Disadvantages of ISDN

The disadvantage of ISDN is that it requires specialized digital services and is costlier.

However, the advent of ISDN has brought great advancement in communications. Multiple transmissions with greater speed are being achieved with higher levels of accuracy.

 

TCP/IP (Transmission Control Protocol/Internet Protocol)

TCP/IP, or the Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet. TCP/IP can also be used as a communications protocol in a private network (an intranet or an extranet).

The entire internet protocol suite -- a set of rules and procedures -- is commonly referred to as TCP/IP, though others are included in the suite.

TCP/IP specifies how data is exchanged over the internet by providing end-to-end communications that identify how it should be broken into packets, addressed, transmitted, routed and received at the destination. TCP/IP requires little central management, and it is designed to make networks reliable, with the ability to recover automatically from the failure of any device on the network.

The two main protocols in the internet protocol suite serve specific functions. TCP defines how applications can create channels of communication across a network. It also manages how a message is assembled into smaller packets before they are then transmitted over the internet and reassembled in the right order at the destination address.

IP defines how to address and route each packet to make sure it reaches the right destination. Each gateway computer on the network checks this IP address to determine where to forward the message.

 

The history of TCP/IP

The Defense Advanced Research Projects Agency (DARPA), the research branch of the U.S. Department of Defense, created the TCP/IP model in the 1970s for use in ARPANET, a wide area network that preceded the internet. TCP/IP was originally designed for the Unix operating system, and it has been built into all of the operating systems that came after it.

The TCP/IP model and its related protocols are now maintained by the Internet Engineering Task Force.

 

How TCP/IP works

TCP/IP uses the client/server model of communication in which a user or machine (a client) is provided a service (like sending a webpage) by another computer (a server) in the network.

Collectively, the TCP/IP suite of protocols is classified as stateless, which means each client request is considered new because it is unrelated to previous requests. Being stateless frees up network paths so they can be used continuously.

The transport layer itself, however, is stateful. It transmits a single message, and its connection remains in place until all the packets in a message have been received and reassembled at the destination.

The TCP/IP model differs slightly from the seven-layer Open Systems Interconnection (OSI) networking model designed after it, which defines how applications can communicate over a network.

 

TCP/IP model layers

TCP/IP functionality is divided into four layers, each of which include specific protocols.

·        The application layer provides applications with standardized data exchange. Its protocols include the Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), Post Office Protocol 3 (POP3), Simple Mail Transfer Protocol (SMTP) and Simple Network Management Protocol (SNMP).

·        The transport layer is responsible for maintaining end-to-end communications across the network. TCP handles communications between hosts and provides flow control, multiplexing and reliability. The transport protocols include TCP and User Datagram Protocol (UDP), which is sometimes used instead of TCP for special purposes.

·        The network layer, also called the internet layer, deals with packets and connects independent networks to transport the packets across network boundaries. The network layer protocols are the IP and the Internet Control Message Protocol (ICMP), which is used for error reporting.

·        The physical layer consists of protocols that operate only on a link -- the network component that interconnects nodes or hosts in the network. The protocols in this layer include Ethernet for local area networks (LANs) and the Address Resolution Protocol (ARP).

 

Advantages of TCP/IP

TCP/IP is nonproprietary and, as a result, is not controlled by any single company. Therefore, the internet protocol suite can be modified easily. It is compatible with all operating systems, so it can communicate with any other system. The internet protocol suite is also compatible with all types of computer hardware and networks.

Limitations Of Internet

1) The quality of information resources might not always be reliable and accurate.

Of course, with so many many websites and webmasters claiming to be an expert in almost anything, we are ending up with stuffs like “learn how to earn online with a 13 year old“. While I don’t blame such approaches, their integrity and experience about the subject is definetly questionable.

 

2) Searching of information can be very tedious. (It IS definetly time consuming)

Let’s a take an example, just google for the word “money“, you will see 10 pages full of resources (That’s only with google, now there are yahoo, msn..etc). So finding what you are exactly looking for, might take you some hours of browsing..

 

3) Internet is definetly not 100% secure.

We cannot neglect things like identity theft, a pc being compromised by a cracker or your email account being compromised..Etc
( Thought: may be you could think about the possible solutions for this situation )

 

Some other critical limitations of using internet marketing as your source of medium.

1. Online Marketing

Online Marketing as people allegedly say does not happen to be of free of cost, there are a lot of things that adds to the cost of internet marketing and they are not at all cheap. Some of the major expenses are the cost of hardware, software, wed site designing, online content and product distribution costs, maintenance of the site as well as server, web hosting of the website and the costliest thing is time, all of these must be considered while planning for Internet Marketing budget and strategies.

 

2. Conventional Marketing

Where conventional marketing helps in spreading awareness as well as selling, the internet is considered as a medium to gain information to most of the customers. There are still many industry and areas where internet marketing is incapable of generating a trust and sale of the product or the service. There are still lots of fields where people prefer the live interaction when they buy.

 

3. Access to Internet

Still, 50% of the world does not have access to the internet and there are many such areas where people are not even literate enough to access the internet. This is a major limitation for internet marketing in the current scenario.

 

 

4. Cyber Crimes

Cyber Crimes are increasing day by day as well as the scams. The rules if cyber security are still not that secure and that leaves a fear in the mind of the people and leaves internet marketing vulnerable.

 

5. Internet Marketing

Internet marketing faces a major current as well as the future issue of “infollution” – the issue of distracting and old data on the internet. There are lots of websites that are decades old and no information is updated on it from a long time. If a customer relies on it and makes a decision, there is a high chance that it can lead to some trouble. This thing is not an issue in conventional marketing as people timely update things in the real world. Whereas there is no such filter available in the virtual world.

 

6. Secure your Website

One major issue and an important question is that “is your website safe?” In internet marketing it is very easy for competitors to attack your website and put in some hack in it, there are a lot of such examples where competitors tried and also succeeded in damaging the brand image via some online hack or negative attacks.

 

7. Internet Marketing

One of the major reason why conventional marketing is not affected that much from Internet Marketing is good old fashioned customer service. The majority of online marketers fail to deliver ideal response programs as well as customer service. There are thousands of website live which has no customer care service and still are running. But, the word travels really fast in this virtual world and if a website fails to deliver desired customer service to even a single customer, there is a high possibility that the customers will spread out a negative word in the industry and news no matter genuine or fake, travels faster in the virtual world.

 

8. Marketing Strategy

One major benefit of Conventional marketing is that it is not that easy to imitate a conventional marketing move. It takes the time to do that and in the meanwhile, the initiative taker gets the benefit of risk. But, if we talk about internet marketing, there are a lot of instances where one successful strategy will be copied in less than 24 hours by your competitors. Thus, you fail to get the desired benefit. Thus, the only motive of this article is that no matter how fond marketers are of the internet marketing, if they have not taken proper precautions and some help of an expert, there is a high possibility of getting a backlash or a complete failure and resulting into a waste of time as well as money.

 

Hardware and Software Requirements

What Do I Need to Connect to the Internet?

To connect to the Internet you need the following four things:

·   A computer.

·   A modem and telephone line (if you are using dial up access) ...

·   An Internet browser (software) and software to connect you to the ISP.

·   An account with an Internet Service Provider (ISP) Souvenirs.

 

Hardware and Software Requirements

Recommended Operating Systems

Windows: 7 or newer

MAC: OS X v10.7 or higher

Linux: Ubuntu

 

Hardware Requirements

We strongly recommend a computer fewer than 5 years old.

Processor: Minimum 1 GHz; Recommended 2GHz or more

Ethernet connection (LAN) OR a wireless adapter (Wi-Fi)

Hard Drive: Minimum 32 GB; Recommended 64 GB or more

Memory (RAM): Minimum 1 GB; Recommended 4 GB or above

Sound card w/speakers

Some classes require a camera and microphone

 

Recommended Software

Supported Browsers

People often ask what browser they should use. There is no single answer for this. Use whichever browser works best on your computer. However, we recommend downloading Firefox and/or Chrome in addition to having Internet Explorer or Safari.

Firefox

Chrome

 

Other important software

Java

Adobe Flash Player

Adobe Reader

These things work together in the following way:

The Computer is essential.

The Modem is necessary if you are using a telephone line to access the Internet. It translates the language that computers talk into a language that can travel across the phone lines, and vice versa.

The ISP is your gateway to the Internet. You access the ISP over the phone line, and the ISP will connect you to the Internet. The ISP provides you with e-mail and access to the Internet. It does this through thousand of dollars worth of hardware and software, which the average user can not afford. You will have an account with the ISP - you will pay $X per month in return for accessing the Internet through the ISP. This account will come with a user name and a password that you use to log on to the Internet.

You need two lots of software to connect to the Internet. The first is the software that connects you to your ISP. This is different for each ISP. Some ISP's will give you a disk with the connection software on it. Other ISP's will use the connecting software that comes with the operating systems Windows 95, OS7 and OS8. They will give you the settings to put into this software.

The second lot of software you need is a Browser. Browsers go and get web pages and display them on your computer. The two most popular and commonly used browsers are Netscape Navigator and Microsoft Internet Explorer. These browsers also provide the software for e-mail and to read Usenet newsgroups. If you have a browser that is just a browser, you will also need software for e-mail and for reading newsgroups.