Points discussed in this article:
- What is softphone?
- Technical background
- Usage and benefits
What is softphone?
A softphone is an application that substitutes physical IP telephone set and let users make phone calls over the internet or another IP network. The software can be installed on a variety of devices, e.g.: workstations, portable computers, tablets or cell phones. A softphone is usually used with a headset or with a USB phone. Often softphone interface emulates traditional telephones and contains phone keypad with which a user can interact by usual way.
Softphones can be based on a variety of platforms and technologies.
Softphones appeared with IP PBX but now are used more often as clients of virtual PBXs or tools for phone calls via the internet.
Usually, softphones are connected to a VoIP networks of service providers. The latter provides a number of services to the user. in order for this to work, softphone should support a set of protocols and audio codecs defined by providers.
For example, the most common protocols are Session Initiation Protocol (SIP, IETF standard), XMPP (IETF standard), H.323 (ITU standard), skype (proprietary), IAX (Asterisk platform), and other proprietary protocols.
Usually, softphones support a variety of audio codec, for example, G711, G728, G729, iLBC.
Softphones functionality is usually high and exceeds the functionality of a telephones sets. Softphones support common features of telephone sets, such as DND, mute, hold, transfer,flash, keypad. On top of that, they support additional features: balance indication, presence status indication, corporate address book, instant messaging, video, HD audio and so on.
Usage and benefits
For personal use, softphones are usually used for free peer-to-peer long distance calls.
In business, use cases are more diverse.
At first, replacement of telephone sets means saving since most softphones are free or cheap.
Second, employees, especially remote or frequent travelers, can take their office phone anywhere and be connected to corporate PBX at any time. Even more, there calls to colleagues will be free or very cheap.
Next, sometimes softphones with a headset are convenient for office workers, especially with high call volumes.
And the last, softphone is an easy way to integrate business applications (CRM, help desk and so on) with a business phone system.