Telecommunications Place

Now with Comcast you can get all three of your home telecommunications services on one bill for triple the convenience and loads of savings also. Comcast has branched out into the phone and internet service business and what they are now offering is three services with total convenience and competitive pricing.

It’s called bundled services and it’s not to be mistaken for the group marketing plans that other service providers are offering that leaves you obtaining your services from three separate companies. There is no savings or convenience in what they offer, or if there is any savings it’s minimal at best. Comcast provides all of these three services in house and you will only receive one monthly bill that covers all of the services that you are receiving from Comcast.

Comcast has always been the leader in TV programming and they have just finished a complete upgrade of their entire service infrastructure. They are completely digital now and that means that you are always guaranteed a clear picture and pristine sound on what ever it is you are watching.

Only a cable service provider can deliver you one demand pay per view and now Comcast has two on demand pay per view options. They now have On Demand pay per view or Premiums On Demand subscription service for your pay per View options.

Comcast’s flat rate phone service is also entirely digital and you will be surprised at the difference digital makes in phone service. Because digital phone service is far more efficient Comcast has lots of savings to pass onto their customers. For starters all twelve of your phone convenience features come free of charge and this includes call forwarding, call waiting, caller ID and voice mail just to name a few of them.

Because it’s a flat rate digital phone service your entire long distance calling is free of charge in the U.S. and Canada, including Alaska, any time day or night, seven days a week. These are all the things that other phone service providers run up their customers phone bills with, so you don’t have to worry about phone bill surprises with Comcast as your carrier.

With Comcast digital phone service you get trouble free call placing and crystal clear reception always and every time you use the phone. Comcast also has broadband high speed internet service now and it’s the latest in cutting edge technology in internet service. For surfing the net there is no better way to go then broadband high speed to get your through all the doorways faster.

For online group action fast paced online video games there is just no better way to go then high speed cable, because satellite high speed has a slight lag time that is created by the signal traveling to and then from the satellite. It’s not that much, just a faction of a second or so, but it’s all the time your opponents need to lay you out in a tight match.

Comcast high speed internet service also comes with free McAfee anti virus software and free lifetime upgrades in it as well. The great thing about getting all of your telecommunications services from Comcast is that they all come on one easy to understand bill.

The telecommunications market is one that has affected practically every individual in the world. This connects the world to each other through a touch of a button, logging onto the internet or even simply by picking up a telephone. More people are hooked up to the internet therefore, using the net as way of connecting to other people. These ways are as such much cheaper, clearer, convenient and requires very little knowledge in technology.

Telecommunications equipment have come far since the days of sending out smoke signals, delivering hand written letters via a personal postman or by sending a telegram. These have come as far as allowing people to call others through internet telephony, which if the other party has installed the same software is able to contact their friends free of charge. These software programmes require the other party to be registered and add each other into their contacts profile.

One of the most popular voice-over internet protocol (VOIP) is Skype, which allows you to make the free telephone calls, as long as the other person is added or has added you as their contact. Like MSN it works similarly to a messenger service as people are able to message each other. The only other kind of telecommunications equipment needed is a microphone, headset or a specially developed Skype phone to which people are able to phone each other - kind of like a land line.

These only function if one has a broadband internet connection. This allows a faster connection time, better audio connectivity and a reduced amount of lag. This can be a problem for most VOIP users who find themselves listening to a person’s voice which is 30 seconds delayed.

Other types of telecommunications equipment which have taken a further step forward are mobile phone devices. Back during the 1980s when mobile phones were charging an extortionate amount per minute for a phone call, these were heavy duty devices which struggled with providing a clear signal for good quality audio. This was also something more common amongst the rich and wealthy who had plenty of cash to spare.

Mobile phone devices are now far more advanced, are cheaper to use and do not always need to be held against the ear for a good quality conversation maker. Now these babies can be used without even holding the handset, using a hands free speaker, or through using an earpiece for more confidentiality. Many of which now come with video phoning, Bluetooth connection, internet WAP technology, chat room messaging, interactive screens and much more. From being a once so simple device to make calls, now a technological mind field.

If something as simple as a mobile phone device can be made into an advanced communication and information provider then one must wonder on what the future holds for the telecommunications business. People are able to make them visual when making telephone calls to others providing the setting is right and there are no external disturbances. Telecommunications equipment is more of a necessity than they ever have been, especially for large organisations and businesses. These allow for faster transference of information and communication over greater distances.

VOIP stands for Voice Over Internet Protocol. It is an innovative way to talk with others around the world. VOIP has done amazing things for phone conversations and telephone conferences that take place with companies in other countries. The connection is so clear you won’t believe how far away the other party is.

The VOIP process uses the internet connection to route phone calls. In addition to offering the highest clarify in your calls, you will find the cost to be much less than normal long distance services. For those who make a lot of calls outside of their area code, this is a great savings. In fact, the service allows many long distance calls to be billed as local calls instead.

The VOIP is a great option for those on the go for business or leisure. You can get incoming calls anywhere you can get an internet connection. As more internet ports are being added all the time to various locations, the VOIP will soon be usable everywhere you can image.

One disadvantage of the VOIP system is that is won’t operate during a power outage, and that may be a time when you need it for emergency calls. Some VOIP systems are offering a backup battery for this type of situation.

The VOIP phones offer various payment plans to fit your phone use needs. The VOIP pre-paid phone card is very popular. While this is not an actual phone, it allows the user to make the same affordable calls, from anywhere in the world - right from their computer. The pre-paid phone card is a great product for those working or traveling in another country.

It is believed the VOIP will soon replace many home phones and cell phones. An individual will use their VOIP for both. This is because the cost will be less and the service will be better.

Up until now, if you needed phone service you got it from a phone service company that only did that and if you needed internet service you got that from another company that just did that also. If you needed cable TV programming for your TV, then you went to a cable service provider for that and no one gave all of this a second thought.

Finally Comcast has geared up to carry and provide all three of these home services and because they carry all three of them they are in a better position to offer lower rates along with bigger discounts on all of these services. Not only have they built up their service support infrastructure to accommodate telephone and internet service, but they have also completely upgraded their cable service system as well.

They now carry a full two-hundred and seventy-five channels of programming and it is all in digital format. For reliability and clarity in your picture and sound, you just can’t do better than a solid point to point cable service connection and you will see the results when you take a look at Comcast’s entirely new digital picture. They also have a newly upgraded on demand pay per view service now that is loaded down heavy with a broad choice of new releases, as well as plenty of classics for you to choose from.

On demand is so important for a pay per view service, because you never know when friends are going to stop by on the weekend and you are going to need a great movie to watch. For your internet service needs Comcast has the best technology that is available with their new broadband high speed cable internet service.

With broadband high speed, browsing the internet is a breeze and everything just happens instantaneously with the click of your mouse. Music, video and any other data intensive downloads take only moments and its so easy now to build up your music collection with high speed. Comcast also gives you life time McAfee anti virus protection as well as any and all upgrades for life. For video game players there really is no other option other than high speed now if they plan on getting in on any of the fast action group competition games.

Comcast also now offers the latest digital technology in their phone service system and this means problem free calling as well as crystal clear reception on both ends of the line. They have introduced a revolutionary new flat rate phone billing system that has slashed costs to the consumer to rock bottom. You pay only one low monthly fee and get unlimited long distance calling anywhere in the continental U.S. All of your standard phone features are free as well and this includes voice mail, caller ID and call waiting, just to name a few of the twelve features that you get. All of Comcast’s services are included in one easy to understand bill that has one fee that you pay and the result is the best savings possible that you can get anywhere. To find out more about the new services that Comcast offers, you can contact them online.

The iPhone launched by Apple Inc. in 2007, is a multimedia and internet enabled mobile phone with the functions of a camera phone and iPod along with text messaging and visual voice mail. The iPhone even provides Internet services including e-mail, web browsing and local Wi-fi connectivity.

The features provided by iPhone include conferencing, call holding, call merging, caller ID, and integration along with other cellular network features and iPhone functions. The functions of an iPhone even include visual voicemail that permits the users to view current voicemail messages on-screen needing no call into their voicemail. The customers were allowed to buy custom ringtones through the ring tone feature that was introduced on 2007 by Apple.

Usually the iPhone present the text messages chronologically in a mailbox format placing all the text from recipients together with replies. Text messages are later displayed in speech bubbles under the name of each recipient. It is particularly to be noted that the iPhone do not support MMS, instant messaging, and multi-recipient capability.

The iPhone carries a built in 2.0 digital megapixel camera that will help the user in taking and string photographs. Even there are softwares present in that will allow the user to upload, view, and e-mail photos.There is a clear change in the layout of the music library of iPod from previous iPods. It is possible in iPhone to sort the media library by songs, artists, albums, videos, playlists, genres, composers and compilations. The users using iPhone are allowed to purchase and download songs to iPhone from the iTunes Store directly through Wi-fi technology.

The Apple iPhone has the facility of internet connectivity through the Edge network. The iPhone has the facility of email that enables the user to send photo mail messages. The audio facility related to iPhone guarantees digital experience to the user with the hi-tech technology it is associated with. The iPhone also has a built-in rechargeable battery that is need be replaced by the user making it more and more attractive and sophisticated.

Computers are now part and parcel of our daily lives and we often take them for granted. Whether we are starting our car, loading the washing machine or taking cash out of the bank, a computer is behind it.

We are also used to computers talking to each other, necessary when we are booking online tickets or drawing cash from the bank. Computers communicate by the way of timestamps, most computer transactions from sending and receiving emails to saving documents are reliant on a time stamp. Timestamps are merely the time the process commenced, next time you receive an email, check the time it was sent, it is quite possible the email was sent after you had received it, this is because the time on each machine is not synchronised.

For some transactions it is necessary for computers to be perfectly synchronised, even a few seconds difference between machines can have serious effects, such as finding an airline ticket you had booked had been sold moments later to another customer or you could draw your savings out of a cash machine and when your account is empty you could quickly going to another machine and withdraw it all again.

If machines were not synchronised then many time sensitive transactions could not happen so it is important that computers tell the same time. However, what time is best to synchronise to and how to all machines know the correct time?

Clocks and watches are everywhere but if you check the time on more than one device, chances are they are telling time differently. It may be a matter of seconds but as we have seen, seconds can make all the difference.

Fortunately there is an international standard time called UTC (Universal Coordinated Time), and the exact UTC time is broadcast by special radio transmissions or by the GPS network as a time code.

Computers can receive this time code by using a time server. Normally these servers use NTP (Network Time Protocol) which converts the time to a language the computer understands.NTP servers allow computers to synchronise to the exact same time no matter where they are in the world.

Without NTP time servers, computers would be unable to carry out task that we now take for granted such as online shopping, trading on the stock exchange or even drawing money from a cash machine.

Chapter-1
Introduction:- Client/Server is one of the computer Industries newest and hottest buzzwords. There is no generic definition of client/server as it is used to depist number of nature, developing, and anticipateologies. However the general idea is that clients and servers are separate logical entities that work together Attention over a network to accomplish a task. Client-server is very fashionable. As such, it might be just a temporary fad; but there is general recognition that it is something fundamental and far-reaching; for example, the Gartner Group, who are leading industry analysts in this field, have predicted that
“By 1995 client-server will be a synonym for computing.” Most of the initial client/server success stories involve small-scale applications that provide direct or indirect access to transactional data in legacy systems. The business need to provide data access to decision makers, the relative immaturity of client/server tools and technology, the evolving use of wide area networks and the lack of client/server expertise make these attractive yet low risk pilot ventures. As organizations move up the learning curve from these small-scale projects towards mission-critical applications, there is a corresponding increase in performance expectations, uptime requirements and in the need to remain both flexible and scalable. In such a demanding scenario, the choice and implementation of appropriate architecture becomes critical. In fact one of the fundamental questions that practitioners have to contend with at the start of every client/server project is - “Which architecture is more suitable for this project - Two Tier or Three Tier?”. Interestingly, 17% of all mission-critical client/server applications are three tiered and the trend is growing, according to Standish Group International, Inc., a market research firm. Architecture affects all aspects of software design and engineering. The architect considers the complexity of the application, the level of integration and interfacing required, the number of users, their geographical dispersion, the nature of networks and the overall transactional needs of the application before deciding on the type of architecture. An inappropriate architectural design or a flawed implementation could result in horrendous response times. The choice of architecture also affects the development time and the future flexibility and maintenance of the application. Current literature does not adequately address all these aspects of client/server architecture. This paper defines the basic concepts of client/server architecture, describes the two tier and three tier architectures and analyzes their respective benefits and limitations. Differences in development efforts, flexibility and ease of reuse are also compared in order to aid further in the choice of appropriate architecture for any given project.
Chapter-2
History & defintion:-
History The University of Waterloo implemented Oracle Government Financials (OGF) in May of 1996. That moved UW’s core accounting systems to a vendor-supported package on a Solaris/Unix environment and away from locally developed package(s) on IBM/VM. Plans at that time were to move more (if not all) business systems to a single vendor and to standardize on a single Data Base platform (Oracle for both). A very large state of the art Solaris system was purchased with the intention of co-locating these other Oracle supplied services on the same system with the OGF. Network security architecture was planned that involved isolating administrative networks, fire walling those networks with protocol filters and active traffic monitoring. Systems were purchased and deployed to implement that security architecture. Much has changed in the interim. While the OGF now includes more services beyond the 1996 suite the plans to move all business systems has failed. Notably, we require People Soft/HRMS (Human Resources Management System) for Payroll (deployed in fourth quarter 1998) with People Soft/SIS (Student Information Services) to follow some years hence—Oracle was unable to deliver these key components for our business. Also we’ve discovered, while it’s reasonable to require Oracle as the Data Base when other applications are specified, it’s unreasonable to expect that they will be certified with the same versions of the Oracle Data Base and/or the underlying operating system. Technology changes quickly too: the state of the art Solaris system is no longer current. Networks were restructured to isolate administrative systems in the “Red Room” and administrative users throughout the campus. However, the administrative firewall and active traffic monitor was never implemented - recently it’s been dismantled.

Definition: Despite the massive press coverage of client/server computing, there is much confusion around defining what client/server really is. Client and server are software and not hardware entities. In its most fundamental form, client/server involves a software entity (client) making a specific request, which is fulfilled, by another software entity (server). Figure 1 illustrates the client/server exchange. The client process sends a request to the server. The server interprets the message and then attempts to fulfill the request. In order to fulfill the request, the server may have to refer to a knowledge source (database), process data (perform calculations), control a peripheral, or make an additional request of another server. In much architecture, a client can make requests of multiple servers and a server can service multiple clients.

Figure 1 - Client/Server Transactions
It is important to understand that the relationship between client and server is a command/control relationship. In any given exchange, the client initiates the request and the server responds accordingly. A server cannot initiate dialog with clients. Since the client and server are software entities they can be located on any appropriate hardware. A client process, for instance, could be resident on a network server hardware, and request data from a server process running on another server hardware or even on a PC. In another scenario, the client and server processes can be located on the same physical hardware box. In fact, in the prototyping stage, a developer may choose to have both the presentation client and the database server on the same PC hardware. The server can later be migrated (distributed) to a larger system for further pre-production testing after the bulk of the application logic and data structure development is complete. Although the client and server can be located on the same machine, this paper is concerned primarily with architectures used to create distributed applications, i.e. those where the client and server are on separate physical devices. According to Beaver (et al.), a distributed application consists of separate parts that execute on different nodes of the network and cooperate in order to achieve a common goal. The supporting infrastructure should also render the inherent complexity of distributed processing invisible to the end-user. The client in client/server architecture does not have to sport a graphical user interface (GUI), however, the mass-commercialization of client/server has come about in large part due to the proliferation of GUI clients. Some client/server systems support highly specific functions such as print spooling (i.e. network print queues) or presentation services (i.e. X-Window). While these special purpose implementations are important, this paper is predominantly concerned with the distributed client/server architectures that demand flexibility in functionality

Chapter-3
Meaning of client-server:-
Business meaning of client-server:- Client-server is generally perceived to be the next step forward in the operational effectiveness of business information systems. This is illustrated in figure 1, which indicates cumulative gains from a succession of innovations. Business computing started in the 1960s with batch processing. The main innovation in the 1970s was on-line transaction processing (OLTP), which brought information technology (IT) to the desktop, and made it an integral part of business processes. Batch processing and OLTP in combination continue to be at the core of most enterprise’s information systems. Then in the 1980s came personal computing, which made IT universally affordable and dispersed it throughout business enterprises. Now in the 1990s, client-server is generally perceived to be the way of integrating the separate parts of information systems back together. That is its role and its importance.

Figure 1 Perceived business impact of client-server In these circumstances client-server (or client/server) has become a popular brand name that is applied to almost every kind of product, and to all manner of business and technical insights and marketing messages. This tends to drain it of specific meaning; but in doing so, actually confirms its near-universal applicability.
Technical meaning of client-server:- A useful starting point for understanding client-server is the informal definition used by the Gartner Group:
“Client-server is the splitting of an application into tasks that are performed on separate computers, one of which is a programmable workstation (e.g. a PC).” This definition says that client-server is about distributed computing and software architecture (applications are split into tasks that may be on separate computers). It echoes the vital point that client-server is the way to integrate PCs into all kinds of information systems.
Three Generations of Messaging:

Host Based architecture (not a client/server architecture):

With mainframe software architectures all intelligence is within the central host computer. Users interact with the host through a terminal that captures keystrokes and sends that information to the host. Mainframe software architectures are not tied to a hardware platform. User interaction can be done using PCs and UNIX workstations. A limitation of mainframe software architectures is that they do not easily support graphical user interfaces or access to multiple databases from geographically dispersed sites. In the last few years, mainframes have found a new use as a server in distributed client/server architectures
Lan File sharing architecture (not a client/server architecture):- The original PC networks were based on file sharing architectures, where the server downloads files from the shared location to the desktop environment. The requested user job is then run (including logic and data) in the desktop environment. File sharing architectures work if shared usage is low, update contention is low, and the volume of data to be transferred is low. In the 1990s, PC LAN (local area network) computing changed because the capacity of the file sharing was strained as the number of online user grew (it can only satisfy about 12 users simultaneously) and graphical user interfaces (GUIs) became popular (making mainframe and terminal displays appear out of date). PCs are now being used in client/server architectures
Internet Client Server Architecture:- The goal for this class is to build a base of background knowledge that will underlie the rest of the course. In many areas of technology, one gets the impression that the technology as always existed in its current form. But, of course, technology has a history just like any other natural or unnatural phenomenon. So it is for the Internet and the Worldwide Web. During this discussion, we will look first at some of the important developments that have taken- place over the past thirty years that have made the Internet what it is today. After reviewing this chronology, we will look at two of the underlying technologies that support the Internet. The first is Ethernet, the original local area network (LAN) technology and still one of the most prevalent communication systems used to connect computers that are within a few hundred yards of one another. The second is TCP/IP, the software standard that enables computers located around the world to direct messages to one another and to communicate reliably. After discussing the Internet, we will then turn our attention to the World Wide Web, itself. The discussion begins with a review of its basic client/server architecture, in which a client program running on one computer communicates with a server program running on another to request some particular information or that some service is performed. The Web was built using a client/server architecture in which a Web browser (client) communicates with various Web servers to request pages of information or that a program be run through the server’s Common Gateway Interface (CGI). As the Internet/WWW becomes a more general computing and communications infrastructure, this strict client/server relationship is being expanded. One such expansion involves Java. More about these recent developments later in the course, but for now, we will concentrate on the Web’s classic client/server design. The language Web clients and servers speak to one another is called HTTP (Hypertext Transfer Protocol). You will not have to learn HTTP in detail, but you will have to construct basic HTTP messages in order to do CGI programming and you should understand its underlying philosophy and its basic form and capabilities.
Chapter-4
Process:-
Client Process:- The client is a process (program) that sends a message to a server process (program), requesting that the server perform a task (service). Client programs usually manage the user-interface portion of the application, validate data entered by the user, dispatch requests to server programs, and sometimes execute business logic. The client-based Process is the front- end of the application that the user sees and interacts with. The client process contains solution-specific logic and provides the interface between the user and the rest of the application system. The client process also manages the local resources that the user interacts with such as the monitor, keyboard, workstation CPU and peripherals. One of the key elements of a client workstation is the graphical user interface (GUI). Normally a part of operating system i.e. the window manager detects user actions, manages the windows on the display and displays the data in the windows.

Server Process:- A server process (program) fulfills the client request by performing the task requested. Server programs generally receive requests from client programs, execute database retrieval and updates, manage data integrity and dispatch responses to client requests. Sometimes server programs execute common or complex business logic. The server-based process “may” run on another machine on the network. This server could be the host operating system or network file server; the server is then provided both file system services and application services. Or in some cases, another desktop machine provides the application services. The server process acts as a software engine that manages shared resources such as databases, printers, communication links, or high powered-processors. The server process performs the back-end tasks that are common to similar applications.

Client-Server Computing:-
• Single client, single server
• Multiple clients, single server

Client/server is a computational architecture that involves client processes requesting service from server processes Client/server computing is the logical extension of modular programming. Modular programming has as its fundamental assumption that separation of a large piece of software into its constituent parts (”modules”) creates the possibility for easier development and better maintainability. Client/server computing takes this a step farther by recognizing that those modules need not all be executed within the same memory space. With this architecture, the calling module becomes the “client” (that which requests a service), and the called module becomes the “server” (that which provides the service). The logical extension of this is to have clients and servers running on the appropriate hardware and software platforms for their functions. For example, database management system servers running on platforms specially designed and configured to perform queries, or file servers running on platforms with special elements for managing files.

Network Computing Architecture:-
Oracle’s Network Computing Architecture (NCA) can be captured by three concepts:
1.The World Wide Web is a truly ubiquitous service.
2.The Java Virtual Machine is (or will soon become) a truly ubiquitous service embedded within the Web-browser.
3.A three-tiered model for application delivery with an Oracle Data Base engine (on a large Unix server), a light weight Java application on the client, and a mid-tier “forms” server to provide the gateway between the two.
Oracle began shipping Release 10.7 NCA (the web-deployed applications) in January 1998…. 2000 require
With Release 10.7 NCA, Oracle responded to customer feedback on the difficulty of patching in Smart Client. Although the functionality is the same between 10 SC and 10 NCA, Oracle returned in the web-deployed release to a more granular patching strategy. This strategy also better preserves customizations. Since the forms technology runs on the server in the web-deployed release, relining and regenerating after applying patches is now easier. Due to the differences in patching strategy, Oracle recommends customers not use Smart Client and Release 10.7 NCA in the same instance. Oracle will not support such a configuration. Customerncharactermode installations should migrate directly to the web-deployed release
chapter-5
Client-Server Technology:- Client-server technology is best understood if we discuss it in four areas:
1.Personal platforms
2.Server platforms
3.Client-server middleware
4.Client-server tools and services
Each of these areas is distinctive, although there can be overlap between them.
The term platform is used here to refer to a computer platform that is a complete combination of hardware and operating system software.
Personal platforms:- Personal platforms are perhaps the most distinctive area of client-server technology. We define a personal platform as:
A computer platform, which is connected to a network, provides a consistent and intuitive user interface and assisting a personal user to accomplish tasks on behalf of the enterprise. These characteristics are illustrated in figure 2. Personal platforms are relatively inexpensive and immensely powerful, and there is a wide choice of suppliers. Many different kinds of computers can be personal platforms (e.g. MS/DOS PC, Windows PC, OS/2 PC, UNIX workstation, Apple Macintosh, and various hand-held devices); but the most common case today is an IBM-compatible PC with the Microsoft Windows operating system.

Such platforms are now universally affordable wherever they are needed. This has turned the architecture of computer systems inside out: the old focus was scarce resources in the central machine, remote from its users; the new focus is the abundant personal resources now at the fingertips of each individual user. This trend has ever-increasing force, because PC price/performance ratios continue to improve by a factor of two every eighteen months or so. This change of focus aligns with changes in business structure: organizational hierarchies are being flattened, decision-making authority is being devolved, and IT-enabled processes can now provide processes that were formerly provided by office staff. A combined effect of these business and technical trends is personal empowerment of the individual at the desk. PCs provide personal productivity and independence, but this individuality, multiplied by huge numbers of PCs, can also create anarchy. Client-server helps to resolve these problems. The client’s use shared resources (provided on server platforms), not just personal resources; client-server structure enables all the software and hardware resources to be under architectural and management control. It transforms personal computing into inter-personal computing and enterprise-wide computing. These characteristics help to create order, workgroup cohesion, productivity, and flexibility of business process. Although personal platforms are the main economic and technical driving force for the move to client-server, they are only the first of the five technical ingredients identified at the start of section 2.
Server Platforms:-
We define a server platform as:
A computer platform on which software provides IT services for use elsewhere in the system. Ultimately the services are for use at personal platforms; but services are also provided for use at other server platforms. A server platform may provide services via dependent terminals that do not qualify as personal platforms. Almost all kinds of computer platform can act as server platforms. Therefore, there are many different suppliers, and many possible kinds of server platforms, from super computers to PCs. Each is good for particular kinds of workloads, for different qualitative requirements, and in different areas of the price and performance spectrum. User enterprises can select different platforms to match different needs. This breadth of choice is illustrated in figure 3, which shows that the user at a personal platform may have access to services on many server platforms. This also illustrates the shift of focus onto the individual user at a personal platform, who may now choose IT services from many different sources elsewhere in the computer network. The polarization of systems into client and server platforms recognizes distinctions between personal and shared resources. Each personal platform is an independent personal resource, which may be mobile and is exposed to risks of accidental loss or damage. Conversely, a server platform provides a protected, fixed, and carefully managed environment for shared resources.

Figure 3 many server platforms to choose from

Even where the same technology is used for client and server platforms (e.g. PCs with the same kind of hardware and operating system), these distinctions between personal and shared resources should be made. In the limit, the same machine may be both a personal platform and a server platform (e.g. in a peer-to-peer network; see 3.2). As always, the server role brings obligations to guarantee availability and integrity of the shared resources.
Client-Server middleware:-
We define client-server middleware as:
Packaged software to support the separate parts of client-server application software and enable them to work together. This is by far the most complex area of client-server technology. By concentrating the complexity here we are able to keep the other areas relatively simple. It includes many kinds of function, each of which may itself be distributed, and most of which are inter-related. Some of the main areas are:
• Networking services
• Distributed application services
• Distributed systems management
• Distributed security
• Distributed object management
• User interface management
• Print management
• Data management
• Transaction management
• Workflow management Figure 4 is a symbolic representation of this middleware support for client-server application software. It emphasizes the importance of middleware in enabling client-server technology to operate across the whole business scope relevant to the user’s tasks. This may involve interaction across departmental and functional boundaries, and perhaps across enterprise boundaries.

Figure 4 Client-server middleware
Client-Server tools and services:- Client-server systems may be complex, but with well-integrated systems and well-designed user interfaces the technical complexity should not be visible to the user; it is essentially a problem for the application developer and service provider. They need software development tools and professional services to help manage and hide this complexity. Many of the tools and services needed are the same as always, but there are also needs specific to client-server systems. An important general point is that for packaged (”shrink-wrapped”) application software, the user enterprise does not need program construction tools. Packaged client-server application products are now becoming widely available (e.g. distributed office and groupware applications, business accounting applications, personnel and payroll applications). Another important trend is that different tools (and languages) are needed for different parts of modular application systems. The main distinctions are:
• User interface: languages and tools for construction of graphical user interfaces and any application logic intimately associated with them; e.g. GUI tools and Visual Basic.
• Database: languages and tools for the construction of databases, file systems and object stores, and construction of the application logic intimately associated with them; e.g. Data Manipulation Languages and Relational Database 4GLs.
• Business logic: languages and tools for the construction of application logic that is logically separate from user interfaces and databases; e.g. COBOL.
• Distributed processing: languages and tools specialized for distributed processing, and for spanning all the above functional areas (and other technological and organizational boundaries); e.g. Remote Procedure Call (RPC) tools.
• System management: methods and tools for electronic distribution of software, and operation and tuning of client-server systems.
Most of these tools are associated with the corresponding areas of middleware.

Chapter-6
Client-Server architecture:- By looking back over the technology described in the previous section, three kinds of client-server architecture can be discerned.
Basic client-server:- In basic client-server architecture, a personal or centralized application is split into two parts: a client part on a personal platform, and a server part on a server platform. The latter is often a shared resource, such as a filing service, a printing service, a database, or some application-specific function. The terms client and server are used to refer to the hardware platforms and the application software components (often somewhat ambiguously). Basic client-server architecture is illustrated in figure 9 (and has already been shown in more detail in figure 6).

Figure 9 Basic client-server architecture Basic client-server configurations are normally organized around a local area network (LAN). The whole assembly is usually described as a PC-LAN, and consists of many PCs for personal use (personal platforms), plus one or more shared PCs (server platforms). The local server platforms on these PC-LANs usually provide gateways into enterprise-wide and external networks, and to the servers on them. This is illustrated in figure 10.

Figure 10 a typical PC-LAN Although primarily expressed in terms of PCs and PC-LANs, these basic client-server concepts are applicable to all kinds of computers and networks (e.g. PCs, UNIX, mainframes, LANs and WANs).
Beyond the basics:- Beyond basic client-server there is peer-to-peer processing, co-operative processing and standalone processing. The term peer-to-peer processing is used to refer to configurations in which there are no server platforms, and the server parts of applications are located on personal platforms. Networks operating on this basis are referred to as peer-to-peer networks. This is a low-cost way of implementing small PC-LANs, etc.; but the lack of separate server platforms reduces system integrity and leads to system management difficulties. The term co-operative processing is used to refer to configurations in which application software is distributed over separate server platforms, and the client and server ends of interactions are both on server platforms. This includes interaction between separate applications, not just between parts of the same application. The term stand-alone processing is used to refer to configurations in which all parts of an application are on one platform (usually a personal platform). Any client-server relationships between the parts are not externally visible. People also use the terms peer-to-peer and co-operative processing interchangeably, and with various other meanings. This causes confusion and misunderstandings. There are also various other less well-known formulations such as server/requester and producer/consumer. All the main formulations are illustrated together in figure 11.

Figure 11 various formulations of client-server system structure Unfortunately, many people sharply differentiate the other concepts from client-server (by which they really mean basic client-server). This obscures the vital point that all are variants within one unified structure: client-server architecture. It also leads to misleading statements to the effect that client-server (meaning basic client-server) is defunct, and is being superseded by other techniques such as co-operative processing.
General client-server architecture:- A fundamental limitation of basic client-server and of all the formulations in 3.1 and 3.2 is that they define software configuration in ways dependent on hardware configuration. Furthermore, it is often ambiguous whether the terms client and server refer to the software or the hardware. To escape from these limitations and ambiguities, client-server relationship in software should be defined independently of software location, and independently of any classification of the underlying hardware as clients or servers. The essential clarification is that client and server are roles in which services are used and provided (respectively), and these roles occur in a relationship between autonomous building blocks. In such a relationship, one of the participants uses a service (it has the client role) and another provides the service (it has the server role). This is a client-server relationship. Large and flexible configurations can be built up by combination of these simple concepts. This is illustrated in figure 12.

Figure 12 Principles of client-server architecture As indicated in the right hand side of the diagram, a building block may be both user and provider of services. Therefore, it may have client and server roles and may participate in many client-server relationships with other building blocks. It is client or server only in the context of the particular relationship considered. The realization of client-server architecture in software is via programming languages and middleware (not shown in figure 12). The physical realization of client-server architecture consists of networks of separate computers; consequently the term client-server tends to become a synonym for distributed processing. Client-server architecture is only incidentally about PCs, or use of any other particular kind of technology. However, in current circumstances, it is usually appropriate that client-server is viewed mainly in terms of exploiting PC technology (as in the Gartner definition which we started with in 1.2 above). This general form of client-server architecture (autonomous building-blocks, client-server relationships, client role, server role) is a fundamental ingredient of OPEN framework application architecture.

Assumptions:-
1.One client is connected to at most one server at a time. [The customer later refuted this assumption.]
2.Replication is a secondary effect of the existing fat-client architecture; we assume that updates to one server are automatically propagated in a timely fashion.
3.A single client may have more than one session. [Replaced Assumption 1.]
4.All calculated columns (columns that represent behavior rather than aspects) are easily & quickly calculated on the server.
5.Deletion or insertion of a row forces a window update on the client.
6.Transmission of client-server traffic is out of scope.

chapter-7
Architecture Types:- When considering a move to client/server computing, whether it is to replace existing systems or introduce entirely new systems, practitioners must determine which type of architecture they intend to use. The vast majority of end user applications consist of three components: presentation, processing, and data. The client/server architectures can be defined by how these components are split up among software entities and distributed on a network. There are a variety of ways for dividing these resources and implementing client/server architectures. This paper will focus on the most popular forms of implementation of two-tier and three-tier client/server computing systems. Two-tier Architecture:- Although there are several ways to architect a two-tier client/server system, we will focus on examining what is overwhelmingly the most common implementation. In this implementation, the three components of an application (presentation, processing, and data) are divided between two software entities (tiers): client application code and database server (Figure 2). A robust client application development language and a versatile mechanism for transmitting client requests to the server are essential for a two-tier implementation. Presentation is handled exclusively by the client, processing is split between client and server, and data is stored on and accessed via the server. The PC client assumes the bulk of responsibility for application (functionality) logic with respect to the processing component, while the database engine - with its attendant integrity checks, query capabilities and central repository functions - handles data intensive tasks. In a data access topology, a data engine would process requests sent from the clients. Currently, the language used in these requests is most typically a form of SQL. Sending SQL from client to server requires a tight linkage between the two layers. To send the SQL the client must know the syntax of the server or have this translated via an API (Application Program Interface). It must also know the location of the server, how the data is organized, and how the data is named. The request may take advantage of logic stored and processed on the server, which would centralize global tasks such as validation, data integrity, and security. Data returned to the client can be manipulated at the client level for further sub selection, business modeling, “what if” analysis, reporting, etc.

Figure 2 - Data Access Topology for two-tier architecture. Majority of functional logic exists at the client level The most compelling advantage of a two-tier environment is application development speed. In most cases a two-tier system can be developed in a small fraction of the time it would take to code a comparable but less flexible legacy system. Using any one of a growing number of PC-based tools, a single developer can model data and populate a database on a remote server, paint a user interface, create a client with application logic, and include data access routines. Most two-tier tools are also extremely robust. These environments support a variety of data structures, including a number of built in procedures and functions, and insulate developers from many of the more mundane aspects of programming such as memory management. Finally these tools also lend themselves well to iterative prototyping and rapid application development (RAD) techniques, which can be used to ensure that the requirements of the users are accurately and completely met. Tools for developing two-tier client/server systems have allowed many IS organizations to attack their applications backlog, satisfying pent-up user demand by rapidly developing and deploying what are primarily smaller workgroup-based solutions. Two-tier architectures work well in relatively homogeneous environments with fairly static business rules. This architecture is less suited for dispersed, heterogeneous environments with rapidly changing rules. As such, relatively few IS organizations are using two-tier client/server architectures to provide cross-departmental or cross-platform enterprise-wide solutions Since the bulk of application logic exists on the PC client, the two-tier architecture faces a number of potential version control and application re-distribution problems. A change in business rules would require a change to the client logic in each application in a corporation’s portfolio, which is affected, by the change. Modified clients would have to be re-distributed through the network - a potentially difficult task given the current lack of robust PC version control software and problems associated with upgrading PCs that are turned off or not “docked” to the network. System security in the two-tier environment can be complicated since a user may require a separate password for each SQL server accessed. The proliferation of end-user query tools can also compromise database server security. The overwhelming majority of client/server applications developed today are designed without sophisticated middleware technologies, which offer increased security. Instead, end-users are provided a password, which gives them access to a database. In many cases this same password can be used to access the database with data-access tools available in most commercial PC spreadsheet and database packages. Using such a tool, a user may be able to access otherwise hidden fields or tables and possibly corrupt data. Client tools and the SQL middleware used in two-tier environments are also highly proprietary and the PC tools market is extremely volatile. The client/server tools market seems to be changing at an increasingly unstable rate. In 1994, the leading client/server tool developer was purchased by a large database firm, raising concern about the manufacturer’s ability to continue to work cooperatively with RDBMS vendors, which compete with the parent company’s products. The number two-tool maker lost millions and has been labeled as a takeover target. A firm also in the midst of severe financial difficulties and management transition supplies the tool, which has received some of the brightest accolades in early 1995. This kind of volatility raises questions about the long-term viability of any proprietary tool an organization may commit to. All of this complicates implementation of two-tier systems - migration from one proprietary technology to another would require a firm to scrap much of its investment in application code since none of this code is portable from one tool to the next.

Three tier:- Most sophisticated Web based applications, which involve data entry, are based on a 3 tier client server architecture. The 3 tiers are
• The Client (Web Browser)
• The Web Server/Application Server
• The Database Server The tree tier architecture (Figure 3) attempts to overcome some of the limitations of the two-tier scheme by separating presentation, processing, and data into separate, distinct software entities (tiers). The same types of tools can be used for presentation as were used in a two-tier environment, however these tools are now dedicated to handling just the presentation. When the presentation client requires calculations or data access, a call is made to a middle tier functionality server. This tier can perform calculations or can make requests as a client to additional servers. The middle tier servers are typically coded in a highly portable, non-proprietary language such as C. Middle-tier functionality servers may be multi-threaded and can be accessed by multiple clients, even those from separate applications. Although three-tier systems can be implemented using a variety of technologies, the calling mechanism from client to server in such as system is most typically the remote procedure call or RPC. Since the bulk of two-tier implementations involve SQL messaging and most three-tier systems utilize RPCs, it is reasonable to examine the merits of these respective request/response mechanisms in a discussion of architectures. RPC calls from presentation client to middle-tier server provide greater overall system flexibility than the SQL calls made by clients in the two-tier architecture. This is because in an RPC, the requesting client simply passes parameters needed for the request and specifies a data structure to accept returned values (if any). Unlike most two-tier implementations, the three-tier presentation client is not required to “speak” SQL. As such, the organization, names, or even the overall structure of the back-end data can be changed without requiring changes to PC-based presentation clients. Since SQL is no longer required, data can be organized hierarchically, relationally, or in object format. This added flexibility can allow a firm to access legacy data and simplifies the introduction of new database technologies.

Figure 3 - Three-Tier Architecture. Functionality servers handle most of the logic processing. Middle-tier code can be accessed and utilized by multiple clients In addition to the openness stated above, several other advantages are presented by this architecture. Having separate software entities can allow for the parallel development of individual tiers by application specialists. It should be noted that the skill sets required to develop c/s applications differ significantly from those needed to develop mainframe-based character systems. As examples, user interface creation requires an appreciation for platform and corporate UI standards and database design requires a commitment to and understanding of the enterprise’s data model. Having experts focus on each of these three layers can increase the overall quality of the final application. The three-tier architecture also provides for more flexible resource allocation. Middle-tier functionality servers are highly portable and can be dynamically allocated and shifted as the needs of the organization change. Network traffic can potentially be reduced by having functionality servers strip data to the precise structure required before distributing it to individual clients at the LAN level. Multiple server requests and complex data access can emanate from the middle tier instead of the client, further decreasing traffic. Also, since PC clients are now dedicated to just presentation, memory and disk storage requirements for PCs will potentially be reduced. Modularly designed middle tier code modules can be re-used by several applications. Reusable logic can reduce subsequent development efforts, minimize the maintenance workload, and decrease migration costs when switching client applications. In addition, implementation platforms for three tier systems such as OSF/DCE offer a variety of additional features to support distributed application development. These include integrated security, directory and naming services, server monitoring and boot capabilities for supporting dynamic fault-tolerance, and distributed time management for synchronizing systems across networks and separate time zones. There are of course drawbacks associated with a three-tier architecture. Current tools are relatively immature and require more complex 3GLs for middle tier server generation. Many tools have under-developed facilities for maintaining server libraries - a potential obstacle for simplifying maintenance and promoting code re-use throughout an IS organization. More code in more places also increases the likelihood that a system failure will effect an application so detailed planning with an emphasis on the reduction/elimination of critical-paths is essential. Three tiers brings with it an increased need for network traffic management, server load balancing, and fault tolerance. For technically strong IS organizations servicing customers with rapidly changing environments, three tier architectures can provide significant long-term gains via increased responsiveness to business climate changes, code reuse, maintainability, and ease of migration to new server platforms and development environments.

Comparing two and three tire development efforts:- The graphs in Figures 4-6 illustrate the time to deployment for two tiers vs. three tier environments. Time to deployment is forecast in overall systems delivery time, not man-hours. According to a Deloitte & Touche study, rapid application development time is cited as one of the primary reasons firms chose to migrate to client/server architecture. As such, strategic planning and platform decisions require an understanding how development time relates to architecture and how development time changes as an IS organization gains experience in c/s.

Figure 4 - Initial Development Effort Figure 4 shows the initial development effort forecast to create comparable distributed applications using the common two tier and three tier approaches discussed above. The three tier application takes much longer to develop - this is due primarily to the complexity involved in coding the bulk of the application logic in a lower-level 3GL such as C and the difficulties associated with coordinating multiple independent software modules on disparate platforms. In contrast, the two-tier scheme allows the bulk of the application logic to be developed in a higher-level language within the same tool used to create the user interface.

Figure 5 - Subsequent Development Efforts Subsequent development efforts may see three-tier applications deployed with greater speed than two tier systems (Figure 5). This is entirely due to the amount of middle-tier code, which can be re-used from previous applications. The speed advantage favoring the three-tier architecture will only result if the three-tier application is able to use a sizable portion of existing logic. Experience indicates that these savings can be significant, particularly in organizations, which require separate but closely related applications for various business units. Re-use is also high for organizations with a strong enterprise data model because data-access code can be written once and re-used whenever similar access needs arise across multiple applications. The degree of development time reduction on subsequent efforts will grow as an organization deploys more c/s applications and develops a significant library of re-usable, middle-tier application logic.

Figure 6 - Client Tool Migration Figure 6 makes the important case for code savings when migrating from one client development tool to another. It was stated earlier that client tools are highly proprietary and code is not portable between the major vendor packages. The point was also made that the PC tools market is highly volatile with vendor shakeouts and technical “leapfrogging” commonplace. In a two-tier environment, IS organizations wishing to move from one PC-based client development platform to another will have to scrap their previous investment in application logic since most of this logic is written in the language of the proprietary tool. In the three-tier environment this logic is written in a re-usable middle tier, thus when migrating to the new tool, the developer simply has to create the presentation and add RPC calls to the functionality layer. Flexibility in re-using existing middle-tier code can also assist organizations developing applications for various PC client operating system platforms. Until recently there were very few cross-platform client tool development environments and most of today’s cross-platform solutions are not considered “best-of-breed”. In a three-tier environment separate client tools on separate platforms can access the middle tier functionality layer. Coding application logic once in an accessible middle tier decreases the overall development time on the cross-platform solution and it provides the organization greater flexibility in choosing the best tool on any given platform.

The characteristics of client/server architecture:-

The basic characteristics of client/server architectures are:

1) Combination of a client or front-end portion that interacts with the user, and a server or back-end portion that interacts with the shared resource. The client process contains solution-specific logic and provides the interface between the user and the rest of the application system. The server process acts as a software engine that manages shared resources such as databases, printers, modems, or high-powered processors.

2) The front-end task and back-end task have fundamentally different requirements for computing resources such as processor speeds, memory, disk speeds and capacities, and input/output devices.

3) The environment is typically heterogeneous and multiFinder. The hardware platform and operating system of client and server are not usually the same. Client and server processes communicate through a well-defined set of standard application program interfaces (API’s) and RPC’s.

4) An important characteristic of client-server systems is scalability. They can be scaled horizontally or vertically. Horizontal scaling means adding or removing client workstations with only a slight performance impact. Vertical scaling means migrating to a larger and faster server machine or multiservers.

Client-server applications:-
We define a client-server application as:
An application system in which logically separate software components are integrated together via client-server relationships.

In a client-server relationship, one part of an application (the client end) uses a service provided by the other part (the server end). The latter is often a shared resource, used by many clients. Although integrated together via the client-server relationship, the parts remain separate. We refer to them as being logically separate because they need not be physically remote from one another (they might be in the same computer). We describe client-server application software here in three steps: splitting an application, joining separate applications together, and distributed application structure

Splitting an application:-

Figure 5 Application software modularity There are many ways of partitioning application software into separate components. However, the content of most applications can usually be classified under three different technical headings: data management, application logic and presentation. This is illustrated in figure 5. If the application is to be split into two parts (one part on a client platform, the other on a server platform), the split can be made at either of the two boundaries between functions, or inside one of the three functions. Consequently there are five main ways of splitting a centralized or personal application into two parts between which there is a client-server relationship. This is the basis of the popular classification into five client-server styles, which is promoted by the Gartner Group. It is illustrated in figure 6.

Figure 6 Five generic styles of basic client-server structure
The details need not concern us here. The important point is that different styles suit different needs and circumstances:
• The two styles on the left of the diagram are typical of centralized interactive applications that have been adapted to client-server by means of graphical interface technology, terminal emulation, etc.
• The style in the middle of the diagram is typical of object-oriented distributed applications and distributed TP applications in which data and function are encapsulated together behind application interfaces
• The two styles on the right of the diagram are typical of data-centered applications using client-server 4GL development tools and relational database products Some applications combine all three areas of function (presentation, application logic and data management) at the personal platform. Also, different styles may occur in combination at the same platform.

Joining applications together:- One of the great strengths of client-server is the ability to join separate applications together. This can be done in many ways; but upon the principles used in 2.4.1, there are essentially three levels at which applications can interface with one another. This is illustrated in figure 7.

Figure 7 Three levels at which applications can be joined together
The main characteristics and advantages and disadvantages of these three approaches are:
• At presentation level: Interaction at this level is achieved via direct data exchange (DDE) within a window management system, or via scripting; see [Duxbury, 1994], in which software uses an application’s user interface by simulating a human user. This kind of technique is often referred to as screen scraping. It is very useful for accessing legacy applications, but leads to software maintenance problems if the user interfaces need to change.
• At application function level: Interaction at this level is in terms of business functions. Therefore, the inter-application requests are about the business meanings of the application (and not its presentation or database encoding). This has the advantage of keeping their internal designs separate from their external interactions. There are fewer software maintenance problems.
• At data management level: Interaction at this level is by direct access to the other application’s database. This is common practice, but leads to software maintenance problems when application data structures change.
The first and third approaches inhibit potential for change, the second does not. Further distinctions can be made between direct and indirect interaction between applications, synchronous and asynchronous interaction, and externally programmed interaction and internally programmed interaction.

Distributed application structure:- Distributed applications are evolving towards richly connected network structures of the kind illustrated in figure 8. The circles represent separate software components, and the lines represent client-server relationships between them. This is typical of the kind of structure that results from use of object-oriented design and distributed object management.

Figure 8 Complex distributed application There is also large-scale structure of distributed application systems (within which the individual client-server relationships occur). Typically, three tiers of application software can be discerned in the large-scale structure:
• Front tier: Application software (and databases) at personal platforms, providing all kinds of application services, using local resources and remote resources. Typically, the platforms are PCs. This tier is where the greatest amount of computer power and of new application software is now being deployed.
• Middle tier: Application software (and databases) at server platforms, providing the back-end of personal applications, shared workgroup services and task-oriented services. Typically, the platforms are UNIX or PC. This tier provides rapid adaptation to business process change, without needing changes to the back tier. It puts boundaries around the turbulence and uncertainty generated in the volatile world at the first tier, where all the users are. It also provides lateral linkage across the enterprise (e.g. electronic mail services).
• Back tier: Application software and databases at server platforms providing corporate information services. These are usually functionally partitioned (e.g. accounts, manufacturing, personnel). Typically, the platforms are mainframes. This tier provides the core of shared and long-lived information assets that everything else depends on. There are strong guarantees of data integrity, and the applications and databases are stable, and their design changes rather slowly.
This structure separates different kinds of concerns, which used to be bundled together in centralized computing

chapter-8
Important of client server:-
Advantages of Client-Server:-
ØPotential of reduced cost
ØImproved performance
ØIncreased security
ØMore GUI application
ØGives people the opportunity to make change for better
ØBetter SW development tools once established
ØExploits existing H/W, S/W configurations
ØMatches distributed business models
ØScalable
ØFlexibility and cost saving
ØFlexibility business modeling
ØMaximum technology component choice
ØEfficient use of computing resources
ØData interchangeability and interoperatability
ØEnhanced data sharing
ØIntegrated services
ØSharing resources among devices platforms
ØLocation independence data and process
ØTechnology revolution
ØFuture technology
ØRelational databases
ØDisadvantages of Client-Server:-
ØHeavy up-front cost
ØInitial performance decline
ØLack of skilled professionals
ØNeed of rewrite a lot of software
ØNeed for retraining user
ØDependability- when the server goes down, operational cases
ØLack of mature tools
ØLack of the scalability-network operating system (e.g. novel NetWare, window NT server) are not very scalable
ØHigher then anticipated costs
ØHarder to build
ØLess stable
ØSusceptible to network load
ØLacking in the specialists
ØDifficult to debug
ØDifficult to test
Client/Server Business Application Architectures:

Traditional applications architectures have been based on function today, to meet the needs of the business an application architecture should reflect the complete range of business requirements.
Therefore, client/server computing demands a three layer view of the
organization.

1 The user interface layer, which implements the functional model
2 The business function layer, which implements the process model
3 The data layer, which implements the information model It should be noted that this application architecture does not demand multiple hardware platforms, although such technology can be utilised,if the environment is robust and reliable enough and the business is prepared to pay the additional costs associated with workstation and LAN technology.

Business Benefits: - There is a perceived need for vendor independence. This includes application development methodologies, programming paradigms, products and architectures. - Organization have changed from steep hierarchies to flattened hierarchies - Network management is replacing vertical management - There is a change to team based management - The customer should have a single point of contact for all business with the organization - The customer should deal with the same person over multiple contacts. - The user will perform as much processing as possible during customer contact time - The time required to complete the work will be minimized - There is a need for empowerment of staff and audit trail of actions - Multi-skilled and multi-function teams need access to multiple applications

Different types of servers:-

The simplest form of servers are disk servers and file servers. With a file server, the client passes requests for files or file records over a network to the file server. This form of data service requires large bandwidth and can slow a network with many users down considerably. Traditional LAN computing allows users to share resources, such as data files and peripheral devices, by moving them from standalone PCUs onto a Networked File Server (NFS). The more advanced form of servers are database servers, transaction server and application servers (Orfali and Harkey 1992). In database servers, clients pass SQL (Structured Query Language) requests as messages to the server and the results of the query are returned over the network. The code that processes the SQL request and the data resides on the server allowing it to use its own processing power to find the requested data, rather than pass all the records back to a client and let it find its own
Data as was the case for the file server. In transaction servers, clients invoke remote procedures that reside on servers, which also contain an SQL database engine. There are procedural statements on the server to execute a group of SQL statements (transactions), which either all succeed or fail as a unit. The applications based on transaction servers are called On-line Transaction Processing (OLTP) and tend to be mission-critical applications, which require 1-3 second response time, 100% of the time and require tight controls over the security and integrity of the database. The communication overhead in this approach is kept to a minimum as the exchange typically consists of a single request/reply (as opposed to multiple SQL statements in database servers). Application servers are not necessarily database centered but are used to server user needs, such as.
Download capabilities from Dow Jones or regulating a electronic mail process. Basing resources on a server allows users to share data, while security and management services, which are also based in the server, ensure data integrity and security.

Special types of Architecture:

IBM’s System Application Architecture: SAA is a collection of selected software interfaces, conventions, and protocols that are used as a framework for developing consistent, integrated applications across the major IBM computing environments.

Four major components of this architecture are: - Common User Access (CUA) defines conventions for GUI look and feel. - Common Programming Interface (CPI) provides languages, tools, and APIs that give applications greater portability and more consistent user interfaces across multiple platforms. - Common Communication Support (CCS) supports existing communications standards, such as LU 6.2. - Common Applications, written by IBM, will serve as demonstrations of SAA concepts and make it easy for users to migrate between systems.
APPLE’s VITAL Architecture:- VITAL provides a way of building information systems constructed from generalize

“There’s too much to learn!” “Everything changes so quickly!” “I just don’t understand!”

These are all common reactions to the overwhelming challenge of learning to use a personal computer. The volume of information, the pace of change and the intimidating technical language can make learning about computers seem like an unattainable and unrealistic goal.

However, with the right strategy, learning about computers doesn’t have to be impossible. In fact, thanks to numerous opportunities on the Internet, free computer learning courses are available to everyone and, with a structured approach; you can overcome the barriers to learning about computers and find yourself mastering computer skills quickly and painlessly.

The first step on your path to learning about computers is to tune out all of the ridicule from your friends, forget your precocious eight-year-old niece’s computer skills and focus on yourself. You can do this by defining what success means to you. Do this by setting a few compelling and attainable goals that are relevant to you and assigning them realistic timelines. Make sure these goals are observable and measurable so that you know when you’ve achieved them and can celebrate your success.

For example, if you’ve never touched a computer before, you might set a goal of being able to turn the machine on and to launch three of your favorite programs by the end of your first month of learning. Or you might focus on a specific area of learning about computers, such as navigating the Internet, and set a goal of being able to find two free computer learning courses on a program you would like to learn. Your first goal should be challenging, but not overwhelming. If you stay in your comfort zone, you won’t advance, but if you set goals you can’t achieve, you’ll quickly become discouraged. By achieving some success early on, you’ll be more motivated to challenge yourself to learn faster. This will also make learning about computers fun, which will keep your motivation at a high level.

After you’ve met your first goal – and you will! – take a little time out to celebrate your success. Brag to a friend or family member. Treat yourself to a reward for overcoming all the fear, doubt and uncertainty that comes with tackling such a daunting task. Once you’ve tasted a little success and gotten your feet wet, you’ll have a much clearer idea of what you want and need to learn. If you’ve learned how to launch your three favorite programs, you might realize that you really want or need to master one of those programs. If your goal was to navigate to some free computer learning courses, you might soon realize that you need to understand the features and functionality of a specific site. While it’s tempting at this point to dive in and learn all there is to know, resist that temptation, or you’ll risk becoming overwhelmed. Remember to read sections of the web site that will teach you how to use the site properly. You can often find these under sections like FAQs, How it Works and Getting Started.

To keep your learning on track, identify your ultimate goal and then break that down into smaller steps and goals to get you there. Once you’ve broken down your end goal into a collection of smaller, bite-size chunks of skills to learn, make sure you assign dates to each of them so that you have a timeline with which to work. Again, it’s important to challenge yourself, but don’t set timelines that are so aggressive that they seem unrealistic. Once you know all the things that you need to learn and by when, it’s simply a matter of finding the resources for learning about computers by exploring the Internet, bookstores, libraries and classroom options, such as local community colleges. There are also several free computer learning courses online that will get you started in the right direction. Most of these courses allow you to learn at your own pace and will give you a great start to learning computers with little or no financial obligation. With a little research, you can find a reputable online computer learning courses, and be on your way to materializing your goals for learning about computers in no time.

Tackling the enormous undertaking of learning how to use your computer can be overwhelming. However, by breaking it down into manageable tasks and setting your own pace for learning, you’ll be a computer guru on your own terms in no time.

Are you aware of the communication revolution occurring right now that is SMS Text Messaging?

What is SMS Text Messaging?

SMS, short for Short Messaging Service, is a text message service that enables short messages of generally no more than 160 characters in length, to be sent to, and transmitted from a mobile phone.

Mobile phones and the use of SMS, are having an un-deniable impact on our daily lives and the methods we use to conduct business. The fact that SMS also provides an enormous opportunity for companies to interact with their customers, is not really well known.

Some numbers

Consider these figures. The ‘Mobile Data Association’ reported that in the UK alone, in a three year period from 2003, over 75 billion SMS messages were transmitted.

In the US, according to the ‘Cellular Telecommunications & Internet Association’, the number of SMS messages has grown from 930 million per month in 2002, to 1.2 billion per month in 2003.

Recently, in the Phillipines, SMS Messaging played a major role in bringing down an unpopular political regime. Now that’s a lot of SMS messages.

The ‘Australian Mobile Telecommunications Association’, reported that during 2005, Australians sent more than 5 billion text messages. Considering, Australia’s population is only around 20 million, this is extraordinary.

Popular reality TV shows like Australian Idol, Big Brother, Dancing with the Stars, American Idol, and others, use SMS technology to generate millions of dollars of revenue directly from the SMS votes that will be used to determine the winners.

more numbers

A study of various SMS campaigns revealed the following outstanding results:

1. 61% response, 27% reply to a message, 19% visit a web site, 15% visit a store.
2. 94% of messages are read, which explains the high levels of response and brand impact.

During the last few years, SMS Messaging has developed into the most used service in the mobile data area. Also, when response rates, interactivity and cost to implement, are considered, SMS marketing is without doubt the most popular marketing method.
SMS is a high-response-rate method of communication, which can help to acquire and retain consumers, sell and promote products, drive loyalty, and reinforce branding efforts.
Based on current growth figures, SMS Messaging will become an ever increasingly important component in future marketing communications.

Here are 6 reasons why:

1. SMS messages nearly always reach the recipient

Since there is a charge for sending SMS messages, they nearly always reach the intended recipient. SMS messages are forwarded to SMS Gateways, where they are stored until sent. This means, even if the recipient is not immediately available to receive them, or if the phone is powered off or out of range, messages are able to be delivered at the next opportunity. This high rate of deliverability makes SMS Messaging the most effective method of communication available.

2. SMS messages nearly always get read by the recipient

There’s nothing more irresistible, than the tone of an in-coming SMS message to the user anticipating, perhaps, a personal message from a friend. This reason alone nearly always guarantees that the SMS message that you send, will be read.

3. SMS messages nearly always get read within seconds of being received

Mobile phones are carried by their users wherever they go, even in the restroom. Thus when they receive a SMS message promoting a marketing offer from your business, they can’t resist checking it out and they will usually do this, within seconds of receiving your message.

4. SMS messages will usually get you an immediate response

Mobile users are usually addicted to their phones, whether they would like to admit it or not. A well crafted marketing offer, with an incentive to respond quickly via return SMS, will usually result in a response more quickly than via an e-mail or other type of marketing offer.

5. SMS messages are extremely cost effective

Compared to other methods, and considering it’s high deliverability, there is no contest. SMS Messaging is the most cost effective method of communicating and promoting of products and services currently available.

6. SMS messages can be either a 1 or 2 way communication

Using SMS Messaging to communicate or promote products offers a level of interactivity hard to replicate using other methods.

Case Studies

Case 1 – Around 2,500 mobile phone-users in the town of Lulea, Sweden, volunteered to receive SMS messages of special offers from 150 local organizations. The volunteers were sent an SMS for a well known fast food outlet’s burger offer, 25 per cent of the targeted users took up the offer.

Case 2 – A small club wanting to increase their patrons during slow nights during the week, decided to run theme nights. Having invested in maintaining a database of the clubs members, the club owner prepared and sent an SMS message to his member database, offering a 45% off discount for turning up with the text message. This was done the night prior to the event. The promotion was very successful with 29% of those sent the SMS message, taking up the offer and turning up.

Case 3 – A security business needed to automate and centralize their time sheet process for all of their remotely located security personnel. At each site a supervisor was supplied with a mobile phone with allocated SMS text credits. As security personnel arrived on site, the supervisor would text a keyword and an ID number. These SMS messages were sent to a central administration database, where they updated each officer’s individual timesheet. This process was repeated at the end of the day as officers left. The entire timesheet collection process, that used to take up to 2 days, was almost entirely eliminated. Further, because this process automatically updated the administration database, accuracy and prevention of loss of data was ensured.

Case 4 – A software service provider for media and advertising agents working in film, television and photography, wanted to provide casting agents a quicker and more efficient way to find out if their artists were available for castings. This provider leads the industry in casting solutions by combining, Web and SMS technology. All casting job details are entered into a database, and then queried for artist matches based on set criteria. Artists who match the criteria are then sent an SMS message instantly. Messages are only entered once, personalized, and sent to all of the relevant artists. When received, the artist simply replies with a yes or no. As the message is received at the administration database, records are updated immediately. Casting agents benefited by saving time, reducing costs and accurate recording of events.

SMS as an Effective Marketing Tool

Communication is vital in Marketing. SMS marketing makes it possible to directly interact with customers and provides a cost-effective method of data collection. Many leading companies have included this medium in their marketing strategies, and consequently, the number of companies using SMS continues to grow rapidly.

Client database

An important component of using SMS as a marketing tool is a client database. This database should be maintained with other relevant customer and contact information and of course should contain a valid mobile phone number. If applicable to your area, ensure that you are able to personalize your SMS messages by keeping first names in your database.

Ensure your database is opt-in

Perhaps the most vital factor when settings up an SMS campaign. Make sure your member database of mobile phone numbers is opted in. This pre approval for SMS communication ensures prevention of prosecution. Provision of a member opt out process will also help to avoid legal issues.

Keep it benefit focused and relevant

Ensure your marketing is relevant to your target. The relevance of the message is vital for success. Can the recipient see a real and tangible benefit to the message? If not, brand damage could result. Limit SMS messages to no more than 160 characters. Focus your message on benefits and don’t ramble. If messages are more than 160 characters, a second SMS will need to be sent. Avoid this. In addition to doubling the cost, the recipient may be irritated and discard the entire message.

Ensure interactivity by Inviting participation

SMS Messaging is an interactive medium. Invite participation through polls, logos, games, ring tones or vouchers. Use interactivity to obtain information for precisely targeted future promotions.
Stick to the tried and proven techniques of database marketing
Standard database marketing techniques and principles, as used by other marketing mediums, are what SMS Messaging requires. The marketing database should be dissected by various factors as required by particular businesses, including, gender, age, interests, location, purchasing patterns and frequency.

Create confidence with a Sender ID

The presence of a sender ID is useful as it invokes confidence with the recipient, as the receiver knows the source of the received message. A company name, brand or trade-mark name should always be included in the body of the text message.

SMS is a personal tool – Respect it

SMS marketing places your brand and message directly to a tool, that consumers consider highly personal. Marketers need to respect this method of communication and avoid over using the medium. Exercise restraint, and avoid jeopardizing your legal position to use SMS Messaging as a future marketing tool.

SMS as an Effective Communication Tool

SMS Messaging is widely accepted as the most popular and effective communication tool with a movable audience.

SMS can be easily integrated with a companies existing database and also enables the company to automate the dispatch of messages. It can also be sent immediately to large or small groups, manually or automatically. SMS messages can also be scheduled to be sent at preset times daily, weekly or whenever.

Summary

Right at this moment, literally millions of SMS messages are being sent around the world.

Can you see the opportunities for your business?

Sanchartelesystems is an ISO 9001:2000 certified Delhi based Telecommunication Company in India. It provides equipments like that Digital communication, Wireless communication, Mobile Telesystems.

Sanchartelesystems is a growing telecommunication company due to its best quality
Equipments and services. It provides all major communication equipments such as
Telecommunication system, Telecommunication equipment, Telecommunication hardware, Digital communication system, Digital communication tools, Digital communication technology, Wireless Device, Digital equipments, Mobile Telesystem and Network solutions.

Some specific products are:

Digital: Mirra Series 2, Nice Call Focus III.
Analog: Amateur Radio, Mobile Radio.
Accessories:M285S,MC-100,CP-22E,F22,BC-100,SX Series Power Meters,SX-100,SX-200,SX-400,SX-1000,CS-800 - Duplex Phone Patch and Repeater Controller, CSI MODEL CS-900 - Simplex Phone Patch.

It provides best quality products in the field of Telecommunication, Wireless communication and Digital communication. Products of this company are very safe and reliable in use. It also provides services in the fields of communication. Sanchartelesystems have highly trained motivated and qualified engineers in staff. This company also provides service to its esteemed customer’s on-time and every time for sold products. Making a better relationship with customers and customer’s satisfaction is our main motto.

Sanchar has global partners. Its partners are:

KENWOOD CORPORATION:
Started in 1946 KENWOOD is world leader in mobile radios .It has carved out a worldwide reputation as a leader in its field, based on its advanced technologies, innovative R&D manufacturing quality and superb reliability of its product in mission critical application.

EADS:
EADS is a global leader in aerospace, defense, advanced radio communications solutions and related services. The Group includes the aircraft manufacturer Airbus, the world’s largest helicopter supplier Eurocopter and the joint venture MBDA, the international leader in missile systems. EADS employs about 113,000 people at more than 70 production sites, above all in France, Germany, Great Britain and Spain as well as in the U.S. and Australia. Sanchar proudly associates itself with EADS for TETRA systems in India.

Q-MAC Electronics Pvt. Ltd:
Q-MAC Electronics Pty Ltd, a Western Australian based company, was established in 1994 in order to design, develop and bring to market a range of quality niche-market communications products.

Diamond Corporation:
Diamond Corporation Japan has been associated with us to provide excellent antennas to give enhanced permanence to our Radios.

Sanchartelesystems provide its equipments and services all around the India. It has many dealers all around the India such as Delhi, Dehradun, Haryana, Jaipur and Kanpur in Northern Region; Ahmedabad, Bhopal and Mumbai in Western Region; Bangalore and Channi in Southern Region; Bhubaneshwar and Kolkata Eastern Region.