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.
In the United States the Social Security Administration (SSA) is converting its field offices of 63,000 workers from traditional phone installations to a Vo IP infrastructure carried over its existing data network.
Rather than closed architectures, these devices rely on standard interfaces.
Vo IP devices have simple, intuitive user interfaces, so users can often make simple system configuration changes.
They transport media streams using special media delivery protocols that encode audio and video with audio codecs, and video codecs.
Various codecs exist that optimize the media stream based on application requirements and network bandwidth; some implementations rely on narrowband and compressed speech, while others support high-fidelity stereo codecs.
This system may be more prone to congestion than traditional circuit switched systems; a circuit switched system of insufficient capacity will refuse new connections while carrying the remainder without impairment, while the quality of real-time data such as telephone conversations on packet-switched networks degrades dramatically.The steps and principles involved in originating Vo IP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding.Instead of being transmitted over a circuit-switched network, the digital information is packetized, and transmission occurs as IP packets over a packet-switched network.Because of the bandwidth efficiency and low costs that Vo IP technology can provide, businesses are migrating from traditional copper-wire telephone systems to Vo IP systems to reduce their monthly phone costs.In 2008, 80% of all new Private branch exchange (PBX) lines installed internationally were Vo IP.Communication on the IP network is perceived as less reliable in contrast to the circuit-switched public telephone network because it does not provide a network-based mechanism to ensure that data packets are not lost, and are delivered in sequential order.