Internetworking Technology

Archive for November, 2009

Needs of DBMS:

In olden times, information systems working with stand alone systems for different applications each with their own set of files. This type of information systems implied that data, like addresses, chance of duplication in numerous separate systems, such as an employee’s address. It may be held once in both the payroll system and the personnel system. It results in waste of space and discrepancy. There are some possibilities for the address to be updated in one system but not in the other. The problems mentioned above lead to the development of the database approach. While coming to database approach, an organization attempts to build an incorporated database to maintain all the data requirements of organization. Database management systems are good quality at organizing and managing huge collections of determined data. A DBMS is otherwise called as a suitcase where all the stuff is put so that in one place and easy to reach. It protects data from unlawful access and accidental corruption or loss due to hardware and software failures. This allows concurrent access, denoting that a particular data set can be accessed by one of more users simultaneously. Concurrent access may commence superfluous problems. Dams provide mechanism to prevent concurrent access problems.

Components of a DBMS:

DBMS is a bulky software package that carries out diver’s tasks together with the provisions of facilities to enable the user to way in and transform information in the database. On one hand it is a transitional link between the physical database, operating system and the computer, and on the other hand, the users. Fundamentally, in order to store the data and provide a standardized method for retrieving or changing the data, and finally, the users turn the data into information. The requests for specific information with the help of user interface, that is, application programs. Generally, this request is processed in DBMS’s data manager and following the data manager who requests for the specific records to the file manager. Again, the file manager requests the specific block to the disk manager. Finally, he disk manager retrieves the block and assigned it to file manager, which sends the required record to data manager.

While some techniques are based exclusively on user’s necessities, the majority of the techniques are based on what the users acquire. This amalgamation provides considerably stronger protection then individual’s technique. This technique uses tokens system. Such tokens are separated into two categories such as smart tokens and memory tokens.

Smart Tokens:

Smart token is said to be the functionality expansion of memory token, incorporating one or more integrated circuits into the token itself. When used for verification, a smart token is another example of verification based on user’s control category. Smart token needs a user to give something the user knows in order to unlock the smart token for use. Smart tokens provide great flexibility and they are used to decipher different authentication problems. The benefits of smart tokens may vary depends upon the type of it. In general, they give better security than memory cards. It can solve the trouble of electronic monitoring even if the substantiation is done across an open network by using one time passwords. Conversely, like memory tokens most of the problems associated with smart tokens transmit to their cost, the administration of the system and user displeasure. Normally, Smart tokens are less susceptible to the compromise of PINs.

Memory Tokens:

Memory tokens are destined to store information. It needs special reader or writer devices for writing and reading of data from the tokens. The large amount of memory token in a magnetic strip card is affixed to the surface of a card. Generally, application of memory tokens for substantiation to computer systems is the automatic teller machine card. Memory tokens when used with PINs provide considerably more protection than passwords. The main advantage of memory cards are, it is inexpensive to produce. A hacker must have valid token and corresponding PIN together to pretend to be someone else. It is very difficult than obtaining a valid password and user ID combination. It can be utilized in support of log generation not including the need for the employee to key in a user ID for every transaction or other
logged event till the token can be scanned repeatedly.

The characteristics of a programming language will differ from the other program. Some program will be very simple to use and the other alternative will be very hard to work on. The standard feature of a programming language will be the source to judge its performance. Language selection process has started and the importance of its establishment makes a language good.

Ease of Use:

The programming language should be very simple to review and the codes should be easy to execute the program. The effortlessness and clearness of a language is based on its language rules. It should be competent sufficient to give obvious, easy and united set of concepts. The words of the language should look like English.

Portability:

Any language should hold up the building of code in a method so as to it could be spread crossways manifold platforms. System languages must be autonomous of any careful hardware or operating system.

Naturalness for the Application:

The language is hypothetical to have a language rules that assigns the program deal to reveal the basic logical structure of algorithm. A programming language ought to provide a theoretical framework for viewing through algorithms and ways of expressing those algorithms while flowcharts.

Reliability:

The language ought to maintain construction of apparatus that can be predicted to do their proposed functions in a pleasing manner from end to end. Reliability is concerned with creating a computer breakdown free, and therefore is worried with all likely errors. The language is supposed to have the hold up of error recognition as well as deterrence. It should make some types of errors not possible.

Safety:

It is worried with the degree to which the language chains the building of safety critical systems, elastic systems that are fault tolerant fail safe or healthy in the face of systemic failures. The system must always do what is likely to do and be able to recuperate from any state of affairs that might lead to a calamity or actual system danger. Thus safety tries in the direction of make sure that any failure that results in slight consequences and even potentially unsafe failures are handled in a fail safe style. Language can make easy this through such skin texture as built in consistency examination and exceptional treatment.

Other than viruses and threats that harm the computers programs can be called as worms, troche horse and logic bombs. Each and every program can also be utilized as a median to probate all viruses.

Worms:

The programs which are build to penetrate on the illegal data processing programs and change or wipe out the data. Worm programs frequently use system relations to increase from one system to another computer system. Thus worms assault computers that are connected through announcements lines. When worms are active in a system, it behaves like a virus, or involving in many number of troublesome actions. To multiply themselves into numbers, they make use of net medium relying on the kind of networked systems. This network mailing facility is where a worm can send a copy of itself to the other part of the system. Remote execution capability is the area where a worm can carry out a reproduction and even can get into a remote system to other.

Worms employs code word or password breaking in which it is attempts will be made to go into the systems by using usernames or passwords, also by means of using words from any online glossary. It uses a lock in door apparatus in mail programs that allows it to mail instructions to a distant systems authority predictor. It exploits a insect in a system data program, which allows to access a isolated systems.

Trojan horse:

The term Trojan horse is an very old Greek myths. In the duel between Greek and troy, the Greek army barricade the Troy city but were unable to go through within the city. So they thought to deceit the enemy by constructing a large made of wood horse with solders concealed inside clandestinely and presenting it as a get to the Troy Citizen.

The Processing system developed hugely from its prehistoric years to the recent digital years. There are six types of operating system available from batch processing systems to the latest embedded systems.

Batch Processing Operating System:

Batch operating system is one of the first to progress. This operating system permitted only a program to move at a moment. This kind of operating systems can still be identified in few main outlook computers working group of works. The operating system is the reason for allocating the works according to aging and the materials required. Batch processing operating systems usually mix through large counts of recurring assignments on large systems. So, this operating system will be the best matched for any concern to automate their billing and other payrolls. A catalog of staff will be entered in their monthly payout will be computed and corresponding pay slips would be documented by printing. It is helpful for this reason as these events are repetitive for all employees every month.

Time Sharing or Multi-User Operating System:

Time sharing system is normally followed in computer network that allows different users to allow the same information and software programs on the same system. The multi user operating system designs a user file account, which defines the correct data.

Embedded Operating System:

Embedded Operating System refers to the working system which is self-sufficient in the machine and occupant in ROM. As these systems are generally not used for general purpose, these systems are simpler or less source serious as compared to common purpose OS. Computers that use these operating systems are household machines, car management, energy management and traffic control systems.

Multi-tasking Operating System:

We can execute more than a process in the multi tasking operating system. The workstation is buttoned quickly between the processes. Therefore, a user can work more than a single process at a moment.