Perhaps the most interesting aspect of Internet Telephony is the Internet Telephone capability that is now available. It opens the door to much cheaper voice communications than what we have been accustomed to till now.
You can make a call over the internet in one of three ways: computer to
computer, computer to telephone, and telephone to telephone. Right now
the only one of these that is free (except for your usual internet connection charge) is computer to computer. The other two methods require that you go through a service provider.
For computer to computer or computer to telephone you need a microphone, speakers and a sound card. The sound card should be full duplex which allows both people to talk and listen at the same time as you would on the telephone. Since you can somethimes experience feedback with a full
duplex card, a headset is nice to have. There are telephones that can be hooked
to your computer, and devices that allow you to connect a phone to the interenet if you would rather use a phone than a headset.
There are also products available now that can also transmit video. With a PC camera you can let those you speak to see you, and you can use this facility for video conferencing. You can purchase a PC camera for under $100 US.
Computer to Computer
You will need an internet Telephony program to make a call from your computer, and you may have already downloaded one with your Internet browser. Microsoft NetMeeting comes with the full install of Internet Explorer.
The only drawback with this one is that it will not work with a Mac. Others do.
There are several nicely improved Internet Telephony programs.
Once your program is installed, you can just start making calls. Nothing else is needed.
Computer to Telephone
Calls placed from a Computer to a telephone are done by using one of the many currently available services such "Net2Phone". The call is sent from your computer, out over the internet, then to an Internet Telephony gateway at the call's destination which connects the Internet to the telephone system there.
Telephone to Telephone
You can make this type of call in exactly the same way any phone call is made today, but the call is routed over the Internet for most or part of the way. This reduces long distance charges. Your call starts from a telephone, then it's routed to a Internet Telephony gateway, which connects to the telephone to the Internet. You call then travels across the Internet to its destination, is routed to another Internet Telephony gateway that connects the internet back to the telephone network. Your call is then directed to the telephone at the destination.
These days a search in your favourite seach engine or directory for "Internet phone" will bring you many options to look into
Home Internet Telephony Gateways Internet Phone
Web Callback References