Adoption of VoIP

VoIP was adopted by the following fields.

1. Consumer market 

A major advancement that began in 2004 was the introduction of mass-market VoIP services that utilize existing broadband Internet access, by which subscribers place and receive telephone calls in much the same way as they would through the public switched telephone network (PSTN). Full-service VoIP phone companies give inbound and outbound service with direct inbound dialing. Numerous company offer unlimited domestic calling for a monthly subscription fee. This frequently includes international calls to specific countries. Phone calls between subscribers of the same provider are usually free when flat-fee service is not available. A VoIP phone is necessary to connect to a VoIP service provider. This can be implemented in several ways:

• Dedicated VoIP phones connect specifically to the IP system using technologies such as wired Ethernet or Wi-Fi. They are typically designed in the style of traditional digital business phones.
• An analog telephone adapter is a device that connects to the network and actualizes the electronics and firmware to operate a conventional analog telephone attached through a modular phone jack. Some residential Internet gateways and cable modems have this built in capacity.
• A soft phone is application software installed on a networked computer that is equipped with a microphone and speaker, or headset. The application typically presents a dial pad and display field to the user to operate the application by mouse clicks or keyboard input.

2. PSTN and mobile network providers 

It is becoming increasingly common for telecommunications providers to use VoIP telephony over dedicated and public IP networks to connect switching centers and to interconnect with other telephony network providers; this is often referred to as "IP backhaul."

Smart phones and Wi-Fi-enabled mobile phones may have SIP clients built into the firmware or available as an application download.

3. Corporate use 

Because of the bandwidth efficiency and low costs that VoIP technology can provide, businesses are shifting from traditional copper-wire telephone systems to VoIP systems to minimize their monthly phone costs.

 VoIP solutions aimed at businesses have evolved into unified communications services that treat all communications—phone calls, faxes, voice mail, e-mail, Web conferences, and more—as discrete units that can all be delivered via any means and to any handset, including cell phones. Two kinds of competitors are competing in this space: one set is focused on VoIP for medium to large enterprises, while another is targeting the small-to-medium business (SMB) market.

VoIP allows both voice and data communications to be run over a single network, which can significantly lessen infrastructure costs.

The prices of extensions on VoIP are lower than for PBX and key systems. VoIP switches may run on commodity hardware, such as personal computers. Rather than closed architectures, these devices rely on standard interfaces.

 VoIP devices have simple, intuitive user interfaces, so users can often make simple system configuration changes. Dual-mode phones enable users to continue their conversations as they move between an outside cellular service and an internal Wi-Fi network, so that it is no longer necessary to carry both a desktop phone and a cell phone. Maintenance becomes simpler as there are fewer devices to oversee.

Skype, which originally marketed itself as a service among friends, has begun to cater to businesses, providing free-of-charge connections between any users on the Skype network and connecting to and from ordinary PSTN telephones for a charge.