Softphones are software telephones that enable users to place voice calls over the Internet through their computers. In doing so, these applications typically use Voice over Internet Protocol (VoIP); however, they can also use an existing Local Area Network (LAN) too. Choosing the connection can lead to variances in quality, reliability, and even features. That being said, users should defer to their intended usage (business or personal) to decide upon which connection is better suited for them. Either way, softphones enable users to make calls from their PC to a phone line, from a phone to the PC, and/or between enabled computers. In terms of usability and appearance, softphones often mirror physical handsets and can work either as a standalone program (its own window) or embedded in another application of PC program. Either way, functionality is pretty straightforward.

Softphones act the same as a physical phone’s interface would; however, instead of a physical handset, the display is projected on the user’s screen. From there, users can make calls as well as carry out other functionalities by using the mouse, keyboard, and/or keypad. In regards to conversation, the computer’s soundcard is used to provide audio input and output; therefore, users can choose to use a handset (with built in mic), a mic and computer speakers, an analog telephone adapter, or a USB phone. Additionally, it’s common for these applications to include standard functions and features of traditional phones—i.e. speed dialing, teleconferencing, text, IM, video capabilities, call forwarding, and call waiting.

Currently, there are a number of free (and priced) applications available—i.e. Google Talk, Skype, CounterPath’s Bria, etc; however, in order to use a softphone, users will need the application (often called the client), an Internet connection, AND a VoIP service provider.  Why? Because VoIP service providers allot the underlying service which carries these calls. As such, softphones are registered and assigned a number under their provider. While basic softphone workability generally remains the same, other functionalities/features will vary from provider to provider.

Softphone calls travel the same way VoIP calls do, which means they can move over standard internet connection on users’ local networks, wireless networks (Wi-Fi), and even cellular data networks (3G/4G); however, in some cases softphone traffic cannot be distinguished from other software applications’ traffic. Also, users should note that each VoIP service uses different protocols; therefore, one needs to be certain that their VoIP softphone supports the same protocol as their VoIP service.  Inversely, there is some hazard with protocols—i.e. some IP phones use the same protocols as softphones, which leads to competition for bandwidth. While some softphones (Skype, Gizmo, etc.) are pre-configured with VoIP service, others are not. Instead, they are able to support most SIP-based VoIP services.

Aside from functionality, softphones offer diverse adoptive methods. As such, there are a number of ways to utilize this software as you would use a landline. For example, users can buy a Skype phone, use a headset or microphone, or use a USB adapter as an ATD converter. There are also apps for smart phones and tablets, including the iPod Touch, that allow you to use softphones over Wi-Fi.

Typically, Softphones range a variety of functionalities and features; however, they also allot for other advantages including simplified upgrades, greater mobility, portability, flexibility, and greater cost efficiency due to the lack of physical hardware.  For example, softphones do no rely on hardware; therefore, they can be easily integrated within a pre-existing network. This allows for minimal downtime without cutting service quality. Additionally, this enables users to have full usage of their system from any location. That being said, softphones are great for a number of different users including beginners, mobile employees, telemarketers, call center employees, small businesses, and frequent long distance callers.

Additional Reading
Factors To Consider When Comparing Softphones for Business Use
Dedicated Business VoIP Softphones-Comparison