Voice over Internet Protocol or VoIP is a method of transmitting voice communications over the Internet Protocol (IP) networks, like the Internet. The public switched telephone network (PSTN) is bypassed completely by setting up packets of signaling and media channel setup, digitizing the analog voice signal, encoding and transmission commonly known as Internet Protocol.

Ever since the development in 2004, VoIP services have been growing and reaching out past personal computers to DSL, cable, analog phones and more recently laptops and cell phones. Full-service VoIP phone companies make it possible to dial up unlimited domestic calling and for a small fee, international lines. Wired Ethernet or a wireless Wi-Fi device serves as the source for connection to an analog telephone adapter. In other words, an Internet source plus a PSTN are necessary to send a signal on to a laptop or cell phone.

Many smartphones have the capability to download a VoIP service since they are nothing more than a handheld computer integrated within a cell phone. As of 2010, approximately 45.5 million people in the US owned smartphones and to date is the fastest growing type of cell phone segment of the mobile phone market. There are over 50 different models of smartphones available on the market today that operate through iPhone OS, Windows Mobile, Android or Symbian OS, Palm OS or RIM Blackberry computer operating system (OS). All of the features that are now becoming available for gaining information on phone numbers such as reverse phone lookup can now be done from a smartphone as opposed to locating a laptop or desktop computer.

The flexibility of VoIP makes its popularity even more desirable. Traditional phone lines have more difficulties in securing calls while standardized protocols that create a secure environment are already built into the VoIP. Different integrations with other services available only through the Internet are also easy to achieve. Message or data file exchange during conversation, passing information over the web, managing address books, and audio conferencing or retrieving information on your caller by utilizing reverse phone lookup.

If you do not have a smartphone it is still possible to transfer a phone call from a landline to a cell phone by setting up software to automatically transfer calls to your cell phone if you need to leave your landline. Your calls are able to follow you wherever you go by a routing system that transfers phone calls.

The biggest setback to using VoIP with your landline or cell phone is the dependency on electricity. If there happens to be a power failure, not only is your Internet and landline going to go down but also your cell phone if connected through VoIP. Installation of a Universal Power Supply (UPS) system is recommended that would ensure that your landline would keep working during a power outage. 911 calls are also not always routed as adequately as the normal landline phones and in some instances, the name and address of the caller is not received or displayed at the 911-dispatch center.

Some companies have designed a way to use VoIP through the use of a GSM SIM card that have hundreds of countries accessible to international calling or receiving calls through their mobile unit. A VoIP account needs to be set up and the service is not free but much cheaper than making expensive international phone calls. Still other software companies do not require that you purchase a cell phone from them but simply download their software. Vopium has a software package that re-routes an international call as a local call through a gateway. SMS is converted into data and sent as a data package over the Vopium-owned gateway. There are pay as you go services, discounted packages and additional services such as WiFi, SMS, call back, Sync, Just Dial or IM.

Blackberry cell phones have many different options for using free in-network calling via Wi-Fi and 3G in addition to other phone networks worldwide. TringMe is one such feature that actually has phone rates cheaper than Skype. Truphone was one of the first software VoIP available for the iPhone and BlackBerry. The downside is that very few models offer either TringMe or Truphone that makes impractical unless you happen to possess one of these high-end cell phones.

MO-CALL is a VoIP service that seems to qualify for over 2000 phone models and provide hassle free calls to over 200 countries. This VoIP service can be used anywhere there is GSM coverage but some of the international GSM signals are not very good. Still for a good service that supports VoIP for cell phone use, MO-CALL is one of the best to date.

As more and more companies begin to offer VoIP services, regulations will surely come into play. China has recently been investigating companies that offer this type of service and are considering banning from public use in support of government controlled phone companies. The FCC has also been keeping a close watch on North American activities through the use of VoIP. Although VoIP offers more security than PSTN, there are many aspects that have to be considered. Being able to confiscate records from the airwaves has not been successful and terrorism a continuing threat, it will be interesting to watch how this new technology unfolds. As for the residential cell phone user, there are systems in place to offer more options with VoIP than there were ten years ago.