VoIP or voice over internet protocol is a method used for the delivery of voice information or voice transmission technique over the Internet. VoIP is a telephone connection over the Internet. The data is sent digitally, using the Internet Protocol i.e. IP instead of analog telephone lines and this allows people to talk to one another, long-distance and around the world without having to pay long distance or international phone charges. VOIP or Internet telephony also refers to communications services such as voice, fax, SMS, and voice-messaging applications that are transported through the Internet; instead of the use of public switched telephone network i.e. PSTN. In order to use VoIP, a computer, an Internet connection, VoIP software, a microphone, and analog telephone adapter or VoIP telephone are required.

Advantages of VOIP over Telephone calls

• VoIP is less expensive than other telephone systems because international calls using VoIP are generally inexpensive. Calls between VoIP users are usually free and by using services such as TrueVoIP, subscribers can call one another at no cost to either of them.
• VoIP can reduce communication and infrastructure costs by transmitting voice information more than one telephone call over a single broadband connection.

Drawbacks of VOIP

•  Communication on the IP network is less reliable compared to the circuit-switched public telephone network, because VOIP does not provide a network-based mechanism to ensure that data packets are not lost, and are delivered in sequential order. 

• Telephones analog service are usually connected directly to telephone company phone lines which provide direct current to power most basic analog handsets independently of locally available power. Whereas, IP Phones and VoIP telephone adapters connect to routers or cable modems which mainly depend on the availability of electricity or locally generated power. 

• VoIP telephone systems are susceptible to attacks because of the Internet-connected devices.

Industry Overview

The global VoIP industry will see growth with many companies opting for internal verbal communication over vast distances or VOIP services rather than traditional telephone services.

VOIP Industry Industry Current Trends

As per the reports, VoIP Industry will have a growth of $76.1 billion in 2015 mainly due to demand for residential services given by VOIP and the number of residential and small office/home office i.e. SOHO subscribers to use VoIP services is forecast to grow from 179 million in 2011 to 262 million worldwide by 2015.

Major VOIP Industry Players

Some of the major VOIP service providers are Skype, Rebtel, Phone Power, ViaTalk, Vonage, Voip.com, Yahoo! Voice, iConnectHere, BroadVoice, and AT&T CallVantage Service.