Most of us have already used the Internet to make a voice call at some point in time. Skype of course has been around for quite long and other Internet voice services like Gtalk and Yahoo chat popularized free Internet voice communications. Unfortunately, these technologies do not perfectly replicate the traditional PSTN system. With Skype you need to add credit in order to make a call to an external telephone and to receive your own calls, you have to sign up with a special package to get your own contact number. The other networks like Gtalk per se are closed and do not permit you to make calls to someone using another Internet voice service or even a regular telephone. If you’re choosing to go the VoIP route as a replacement for your phone service, you have to make use of a technology like SIP which is specifically geared towards replicating the traditional telephone experience. There are of course many paid services which allow you to do this. But perhaps you would like to sign up for a free account to get a taste of things before you jump in.
There are many free SIP services available though very few of them will provide you with your own telephone number without paying a fee. You will however receive your own SIP URI address and you can combine this with the services of websites like IPKall which give you a US telephone number. This way, you can be reachable for free using the telephone number provided by IPKall. Making outgoing calls to external telephone numbers however is a little more complicated. To my knowledge, only Google Voice calling from Gmail provides this functionality. You can integrate Google voice with IPKall to completely replace your traditional telephone system if you have a PC or smartphone supporting a standard SIP client.
When it comes to choosing a provider for your free SIP address, you can go with several services. GetOnSip is one example which allows you to obtain an SIP URI address to which you can connect from any SIP client. This client can be available as a program on your PC or an app on your iPhone or Android client. Of course, you can always purchase a regular VoIP phone for excellent call quality and reliability as well. Other services like SIP2SIP and Callcentric exist too. Since it doesn’t cost you anything to try the services out, you might want to create accounts with all of them to see how reliable they are. If you like your service, GetOnSip will allow you to upgrade your account to serve as a fully functional telephone replacement with your very own contact number. Callcentric allows you to do this as well.
We’re still in the early days of public VoIP adoption. New providers offering enhanced services are likely to keep popping up. Keep an eye out for them to take advantage of any additional functionality they offer.