For those of you who haven’t switched from landline to internet telephone, or VoIP, This is a major step. The fact is the number of VoIP subscribers in North American nearly doubled from 2006 to 2007 and is expected to continue growing rapidly through 2012, with an average growth rate of 37 percent annually.  Some said VOIP will replace traditional telephone service at some point. The only question is when should you jump in?

If you have a telephone and high speed internet access, you are already a VOIP candidate. Here's an overview of what to look for before you take the VoIP plunge. It is by no means complete and some of these may not apply to all people.

Pros:

Comparing with regular phone service, the most obvious advantage that VOIP has is its low cost. For example, if you have a high speed Internet connection, you can make PC-to-PC phone calls anywhere in the world FREE. PC-to-phone connections usually charge some fee, but usually it’s much cheaper than regular phone service.

If you are willing to scommit, you can sign up with a VOIP service provider for a monthly fee and get unlimited calls within a specified geographic area. For example, most VOIP services have a unlimited plan around $20-30/month in the United States allow connections anywhere in North America for no extra charge. International calls are charged at a modest rate. In addition, features like call forwarding, call waiting, voicemail, caller ID and 3way-calling, are included with VoIP at no extra charge.

Because VoIP is relatively new, there is a possibility of having free service by referring your friends and family to use the same service. Many of the service providers have a customer referral program.

Another advantage is portability. A VOIP phone has an address built into it that is unique to your phone. This means that in most cases, you can take your VOIP phone with you and use it anywhere that a broadband Internet connection is available. Obviously, there are exceptions, but generally speaking you could take your VOIP phone with you on a trip to oversea even if your service was based in New York.

You don’t necessarily need a VOIP phone to get portability. Some providers of computer based VOIP services offer a Web interface. This interface allows customers to log in and place calls from anywhere in the world, so long as a broadband Internet connection is available. This should be a serious consideration if you have employees that travel a lot and make a lot of calls from the road. The service isn’t as convenient as a cell phone, but it is usually a whole lot less expensive and it works in foreign countries where a cell phone may not.

Cons:

The biggest concerns relate to service quality and reliability – take SunRocket. This new defunct VoIP provider collapse suddenly last year. VOIP also has sound quality and reliability problems. Data sent across the Internet usually arrives at its destination scrambled. E-mail and documents can be reassembled in the correct order when it arrives. Voice data also arrives scrambled, but it's more complicated because of the real-time nature of VOIP. Some data packets may have to be dropped when they don't arrive in time, in order to make voice connections with the least delay. This can cause brief silences in the audio stream.

Your internet connection speed and the distance of the call are the two biggest factors in the quality of the call. If you are in a high-traffic area this may also cause some loss in the quality of the conversation. Once again, technology is constantly being improved on and this is becoming less and less of an inconvenience.

Aside from the various sound quality issues, there are also a few practicality issues that you need to consider. For example, if you are considering a computer based VOIP system, you must remember that you will not be able to place or receive calls unless the computer is turned on, and the VOIP software is running.

Another practicality issue is a VOIP system (computer or VOIP phone based) is useless during a power outage. Battery backups and power generators that provide electricity are the current solutions to this problem.

Emergency (911) calls are another major concern for many potential customers as well. In the event that you need to call 911 but can't speak or have to leave, your call can be traced when dialed from a traditional phone. For VoIP, a technology called 'e911'is being developed and allow VOIP calls to be routed to the correct 911 dispatcher. U.S. Federal law mandates that voice-over-IP offer Enhanced 911(E911), however, some service providers charge extra for it. Whatever service you end up with, you may need to log in to you Web-based control panel and manually activate E911. Don’t forget this important step.