• Price: They are very cheap compared to traditional phone providers. In fact, there are some plans that offer all-inclusive local and long distance dialing packages for as little as $17 a month. These often include Canada, Puerto Rico, and other countries in their long distance rates. Additionally, international calls are typically cheaper than traditional land line phone plans.
• 911 calls: These are generally available with most VoIP providers. However, support for 911 is highly variable, depending on the provider and geographic location. Calls are routed to a different facility than landline calls so it's not guaranteed that your name and address information will display at the call center. VoIP providers are improving 911 dialing and varying degrees of support have been achieved. If this is a concern for you, make sure to ask different providers what level of service is provided in your area.
• Phone number transfers: Most providers are able to port your old phone number over to your internet phone service. The drawback is that it may take anywhere from a week to a couple months for your old number to transfer to your VoIP account. You will be issued a temporary number to use in the meantime, but the longer it takes for the number to transition, the longer you will be paying for two phone services: your VoIP line and your land line.
• Tax savings: A typical traditional phone bill can carry $10 or $15 in tax and regulatory fees. By comparison, VoIP providers may assess only a dollar or two in regulatory costs. For the time being, VoIP users can avoid paying many of the state and regulatory fees that traditional phone providers charge so tax savings from VoIP services are currently an advantage.
• Travel connection: No matter where you connect your telephone adapter to the Internet, the service behaves like you are at home. If you are going on a business trip, you can plug your phone into hotel broadband connection and make calls from your office phone. You not only avoid paying cell phone roaming charges, but calls to your office line will ring at your location.
• Multi-phone options: Many VoIP providers will offer more than one phone in the forma of a multi-handset cordless phone. All you have to do is plug the base into the VoIP box and then place the other handsets where you need them.

These were some of the great advantages to using internet long distance. With every good thing there is some bad though. The biggest disadvantage is that VoIP is not as reliable as traditional phone service. VoIP services run over the shared Internet, which was not designed for real-time applications like voice. Some people complain of having stuttering, clipping or prolonged drops in calls. These interferences can usually be traced to heavy traffic on your Internet network. In addition, power outages may interfere with your service. When the power goes out, so do the modem and telephone adapter your VoIP phone relies on. If this is a concern for you, consider buying a universal power supply that keeps your desktop PC running during a power interruption.

In summary, combination internet and long distance plans have many advantages. You will have to decide if the monetary savings and convenience is worth not having the reliability.