Neel Nirjon

VoIP - Voice Over Internet Protocol - is a very popular buzzword in the Internet world.
VoIP makes communication possible without telephone wires, telephone exchanges and even
without telephones. You can make voice calls free of charge or at a minimal charge over
internet.

If VoIP can give the same quality and standard of voice as in normal telephones then
there will not be any need for telephone exchanges any more. People will change to free
or cheaper VoIP alternative sooner or later.

The VoIP service is available in two types. Free service and cheap service. Skype is a
free VoIP service. While services such as Phonewala, HCL, sathyam provide payable VoIP
service. You can download Skype software from www.skype.com .

In payable VoIP service PSTN (Public Switched Telephone Network) plays a part. Therefore
you can call any other phone number through this service. The called person may have
subsribed to the VoIP service or maynot have subscribed to the VoIP service, you can
still make calls to him. Generally the subscribers of the same VoIP service provider can
talk with each other freely. The free VoIP service does not use PSTN. Therefore if you
are using the Free VoIP service then you cannot call other telephone numbers and vice
versa. But you can use the free VoIP service to talk with each other using computers
conencted to the internet.

Ok, now you have decided to try and use VoIP. What are the requirements to use VoIP?
You computer should have sound card, Microphone and speakers. If you have a headphone
then it is better. And then you should have internet connection. Broadband connection is
better.

In 1999, Internet Society, introduced the Session Initiation Protocol (SIP). SIP protocol
is used to find out whether the computer that you want to call is currently connected to
the internet and is available for making a call. Even internet phones use this SIP
protocol.

Earlier I mentioned that using VoIP you can make free calls between computer to computer. You can also make phone calls from your computer to another phone but at a cheaper rate than the normal phone charges.

If you compare VoIP calls to a normal phone to phone call, it is like comparing the quality of a mobile call and a land line call. Many agree that the quality of a land line to land line call is better than the mobile to mobile call. Similarly the quality of the VoIP calls as compared to phone to phone call is slightly below standard. In VoIP, your voice is converted to digital signals and packed into small data packets and then sent over internet. There is no guarantee that these data packets will be received in the same order in which it was sent. The data packets may get mixed. Therefore in order to get all the data packets and arrange them in order it may take some time and hence there may be delay. This is called 'Jitter'.

If some data packets take too long to arrive then the routers may reject these packets. This will cause 'Packet Loss'. Therefore the speech may be intermittent and sometimes irritable.

And some argue that VoIP is crackable and crackers may evesdrop to these data packets and listen to your conversations. But even normal telephones can be tapped. The VoIP technology is fast evolving and some VoIP providers use Public Key Encryption to encrypt the data packets and hence cannot be cracked.

To read more about VoIP and to download some free VoIP software visit m-indya.com.

Have you noticed that the CDs that you buy or the CDs that comes with books runs automatically when you insert the CD into your CD drive. This is because of the 'Autorun' facility in the CDs.

But using this Auto Run feature you can only execute executable programs. Therefore the webpages and any other files cannot be opened automatically using Autorun.

Imagine that you want to copy the powerpoint presentation that you created or the Word document into a CD and pass it to your friend. Will it not be nice if the powerpoint presentation or the document opens automatically when the friend inserts the the CD into his computer?

Now every computer comes with a CD writer. You may wonder whether the CDs that you create using your CD writer can use the Autorun facility. Yes you can.

You have to create a file named 'autorun.inf'. You can create this file using a normal notepad. You have to copy this file in the root folder of the CD. If you want to use any icon then you can also copy an icon file into the root folder.

How to execute an executable file in a CD automatically.

For example assume that you have a myprogram.exe file and myicon.ico file. And you want to run myprogram.exe file automatically when the CD is inserted

Keep both these files in the same folder.

Open a notepad and type these three lines in the notepad

(autorun)
open=myprogram.exe
icon=myicon.ico

save this file as 'autorun.inf'.

If your executable file is not in the root folder then you have to specify the full path. (eg. open=myfoler/myprogram.exe)

To create autorun cds for non executable files

If your file is not an executable file like .xls, .doc, .htm, .html, .mp3, .wma, .wav, .mpg, .avi, .jpg, .bmp, .zip or any other file then how to write the autorun.inf file.

Let us assume that you have index.htm file as the autorun file. Then the autorun.inf file will be as follows:

(autorun)
open=start index.htm
icon=myicon.ico

In this case when you insert the CD, a small black window will open and close very fast and then you will see the index.htm file in Internet Explorer.

If you do not want the dos window to open then create the autorun.inf file as below:

(autorun)
shellexecute=index.htm
icon=myicon.ico

However the shellexecute will not work in Windows 98 or older versions. It will work in Windows XP and the newer versions of Windows. In earlier versions you can use the DOS batch file. So you will have one more file autorun.bat in addition to autorun.inf

(autorun)
open=autorun.bat index.htm
icon=myicon.ico

and the autorun.bat file will as follows:

echo off
"start % 1
"exit

How to use autorun.exe

In the above example we used two files autorun.bat and autorun.inf. However the use of autorun.bat is not a wise option. Because a batch files cannot handle errors.

Therefore you can use the free autorun.exe instead of autorun.bat

autorun.exe file is provided by Tarma software research freely. Anybody can use this software. You can download autorun.exe from www.tarma.com/products/index.htm . Download this file and copy it to the root folder of the copied CD.

The autorun.inf file should be as follows:

(autorun)
open=autorun.exe index.htm
icon=myicon.ico

These days we hear a lot about broadband Internet connection. In this article we will discuss the basics of broadband and tips to choose the right broad band plan for your home or office.

What is Broadband?

The definition of a broadband connection may differ between different countries. But generally you can say that any Internet connection with a minimum speed of 256Kbps and above can be considered as a broadband connection.

In a 'Dialup' connection, we dialup whenever we need to connect to the Internet and then close the connection when we have finished using the Internet.

But you can connect your computer to Internet 24 hours a day and 7 days a week. In other words it is 'Always On'. Broadband connection is an always on connection. Your computer will be always connected to the Internet.

While using a dialup connection the maximum speed of the connection is only 56Kbps. Moreover when you are connected to the Internet using your phone dialup line, you cannot make or receive phone calls.

Broadband may be available in your area in any of these forms, Copper, Fiber Optics, cable, ADSL, IP VPN or Wireless.

What you need to ask before choosing your broadband provider.

• Which broadband technology the provider is using
  
• What is the monthly subscription and what is the one time set up fee
  
• What is the speed of the broadband? Most of them just tell you the download speed. Ask them about the upload speed also.
  
• What is the bandwidth allowed? That means how much data can be downloaded or uploaded. If there is a limit then what is the charges for additional data usage.
  
• Is free email provided? If yes what is the storage capacity
  
• What software and hardware are required to use that broadband connection. Is the hardware proprietary or can be bought from anywhere?
  
• Is the installation free or you have to do it yourself
  
• What are other conditions such as contracts etc.
  
• What is the support provided?

We measure size of files created in computer by kilobytes, megabytes. We measure modems speed by bits. Let’s see what they denote and let’s see some difference between them.

BIT: In the computer-associated measures this is the smallest one. No file can be in the measures of bits; its value is 0 or 1.
BYTE: combinations of 8 bits are called one byte. To create a file that containing one byte of data is very hard.
KILOBYTE (KB): proximately it has 1024 bytes of combinations. While downloading a file from net we denote it by the units of kilobytes.
MEGABYTE (MB): combinations of 1,048,576 bytes (or) 1024 kilobytes are called 1 megabyte.
GIGABYTE (GB): combinations of 1024 megabytes are called 1 gigabyte. This unit denotes capacity of hard disk.
Now we can fix this unit to some more devices.

* We can store 1.44 MB of data’s into a 3.25 inch floppy.
* In a compact disk we can store 650 to 700 MB data’s. But we won’t completely utilize the space available in cd.one cd contains the space equals to 450 3.25 inch floppy.
* A 20 gigabyte hard disk contains the space equal to 31 cd’s.(i.e.)14,222 floppy’s data.
* In an ordinary dial up connection .it takes 7 to 10 min’s for download a 1 Mega byte file.
* A normal single text page will be in 4 KB when it is changed as a file.

To find the size of a file, just right click on it .now you got a menu and then select the “PROPERTIES” from it. Now you got the size of that particular file.