Computer Networking

plz tell me yar what is the types, function & evolution of operating system

MAC Address

It is basicaly the spine of your computer. Its purpose is to run programs and such. Without it youd just have a box and a screen with fancy wires.

four times faster than average

layer 3 , network layer .

A multiprocessor OS. Mac OS, Windows, and Linux all currently support this(as well as many others).

The first web browser, WorldWideWeb, was graphical. ViolaWWW was the first one to achieve any popularity, released a year later in 1992. A year after that, NCSA Mosaic was released, and became even more popular.

http://www.cisco.com/en/US/ts/fn/100/fn15229.html

A DoS attack where fragmented packets are forged to overlap each other when the receiving host tries to reassemble them.

A data mart is a data repository that gathers data and similar items from certain users or workers. Its characteristics include being focused on one subject like finances or sales, only gathering data from a couple sources like the external data or central data warehouse, and being controlled by only one source.

A broad question, with equally broad answers. Computers are useful in many ways, from organizing complex data sets, storing large amounts of data (including WikiAnswer), interpreting said data (such as finding charts, plotting out data, trending and detrending data) displays of virtual worlds, communicating and associating with others, dealing with complex physics or engineering simulations... Really, the limit to the computer is more the data storage capacity and the speed of processing. Everything else is up to the user and programmer.

Just solve the problem with the principles learnt in class.

Several computers attempting to connect to the same router at once, router processes one, then the next, then the next, etc..

No

The easiest way to explain this is, as you suggest, by an example. So I'll give you an example.

Let's suppose I'm going to write a piece of software that students at a school can use to find out what their current grade is in all their classes. I structure the program so that a database of grades resides on the server, and the application resides on the client (the computer the student is physically interacting with).

When the student wants to know his grades, he manipulates my program (by clicking buttons, menu options, etc). The program fires off a query to the database, and the database responds with all the student's grades. Now my application uses all this data to calculate the student's grade, and displays it for him.

This is an example of a 2-tier architecture. The two tiers are:

1. Data server: the database serves up data based on SQL queries submitted by the application.

2. Client application: the application on the client computer consumes the data and presents it in a readable format to the student.

Now, this architecture is fine, if you've got a school with 50 students. But suppose the school has 10,000 students. Now we've got a problem. Why?

Because every time a student queries the client application, the data server has to serve up large queries for the client application to manipulate. This is an enormous drain on network resources.

So what do we do? We create a 3-tier architecture by inserting another program at the server level. We call this the server application. Now the client application no longer directly queries the database; it queries the server application, which in turn queries the data server.

What is the advantage to this? Well, now when the student wants to know his final grade, the following happens:

1. The student asks the client application.

2. The client application asks the server application.

3. The server application queries the data server.

4. The data server serves up a recordset with all the student's grades.

5. The server application does all the calculations to determine the grade.

6. The server application serves up the final grade to the client application.

7. The client application displays the final grade for the student.

It's a much longer process on paper, but in reality it's much faster. Why? Notice step 6. Instead of serving up an entire recordset of grades, which has to be passed over a network, the server application is serving up a single number, which is a tiny amount of network traffic in comparison.

There are other advantages to the 3-tier architecture, but that at least gives you a general idea of how it works.

Incidentally, this website is a 3-tier application. The client application is your web browser. The server application is the ASP code which queries the database (the third tier) for the question-and-answer you requested.

I hope that helps!

ANKUR MISHRA

YES, the first thing to understand is that there is a vast difference in the two. HUB and ROUTERS (Hub is a Traffic Cop, that is able to focus on the job at hand and perform exactly as needed with traffic. A router is merely a traffic light that performs exactly as commanded.) Now any wireless hub or router will connect any wireless device, but to share a high speed intenet (Cable or DSL)you MUST have a HUB. Hubs are designed to receive a broadband carrier and wireless traffic. But if you having difficulty connecting most likely your wireless devices are not finding or detecting the wireless router or hub. Winxp is unusual, but the best fail safe here is install software for all devices and SHUTDOWN everything! Broadband modems, wireless hub/router and all connected computers. Disconnect power to Broadband modems and wireless hub/router. Wait 10-15 seconds then Plug in power to Braodband modem first. Then wait about 5 seconds and plug in wireless hub/router. Once bioth devices are light up normally turn on all connected computers. The computers should detect the system and self route to compleation.

To verify information you retrieve from the Internet you can use these criteria to evaluate the source.

Open source, such as one of the Linux variants; Ubuntu, or Kubuntu, for example.

Servers

Printers

NAS (Network file systems)

Java is actually a language.Its not a acronym.It was developed by James Gosling.

You have to have a certain type of a router which is able to collect statics about user internet usage. Only some routers have such function.

NO PSTN NETWORKS ARE NOT RELIABLE. The PSTN is he telephone network that links the world together.

The 1st answer has some truth to it, but most of the time (except in the case of fios of other fiber services) you do use the PSTN (Public Switched Telephone Network) to connect to the internet as is in the case of dial up and dsl. However the internet is partly a pstn network and when is the last time the entire internet went down, all across the world. The internet is the worlds most reliable network, and the largest. How the PTSN works, is a whole book (or two) in its own, being compromised of millions, possibly billions of miles of cable and many various satellite, radio, and cable networks within its self. The electrical grid is much less reliable since outages happen several times a year while I've only had mabye 1 phone outage in my life.

Sometimes outsourcing is the best option for such companies. By doing this companies get the professional services without any capital investments.

You need protocols in computer networks because computer networks consist of devices and software made by many different vendors. The only way to ensure compatibility among them all is to have common documents (i.e. the protocol specifications) that describe the mechanics and formats of all the data exchanged over the network.