Voice over internet protocol is also called IP telephony, Internet telephony or also broad band phone. VoIP internet telephony works in the same manner as data transfer on a network. Protocols that determine the aspects of connection and transfer of data are used to transfer data over the network. The protocol that is used to transfer voice over the IP network is called the Voice over IP or VoIP protocols. The network voice protocol was invented for the ARPANET in 1973. It was an experimental protocol that has now realized into the commercial protocol. VoIP Wireless Phone is the present realization of this experiment.
Intranets and VoIP
The Private branch exchanges were designed to automate the telephone communication systems. With the advent of microprocessors these were used in the PBX and hence it was easier to integrate VoIP as well. Integration of VoIP helped save money as the transmission in the form of IP packets was cheaper than a dedicated connection between two ends.
If you have an intranet and a PBX as well you could enable VoIP by connecting an IP gateway between your PBX and intranet. Thus routing calls through the data line and saving cash. Directing long distance calls and international calls via data lines is an effective way of cutting your bill on communication.
VoIP can be used internally as well over the intranet. The advantage with this is that you need not buy a separate PBX for voice communication. VoIP over the intranet data lines is more predictable as the network traffic and bandwidth is determined in advance. More sophisticated VoIP programs could be used for less data loss, full duplex, real time voice communication
Working of VoIP
Traditional telephony used analog signals. Digital technology made the process more efficient by converting analog signals to digital signals and then compressing them. This increases the speed of transmission and lowers the bandwidth requirement as well. VoIP Equipment uses the Sessions Initiation Protocol or H.323 for defining the communication between devices. H.323 is designed for video conferencing has a wider range of applications when compared to SIP. But SIP is more robust when it comes to voice transmission only.
VoIP Basics the handshaking signals that are shared between the two ends to establish a connection. In the traditional telephone system these were achieved using circuit switching methods. For connection to be established and provide you good voice quality you need a cable modem for your internet connection or a different type of telephone system. High speeds are essential to a voice connection. The connection between the two points is maintained as long as the conversation goes on. The IP packets are transferred between the two points using a real time protocol. Similar to the telephone system, VoIP providers charge you a flat rate according to minute.
There are a few Advantages of VoIP that make people adopt this technology.
• Most operating system software now comes with VoIP ability. Application software that provide net based messaging and voice conferencing offer you the ability of a voice chat and even video conferencing. Therefore there is no need of purchasing additional equipment.
• VoIP is beneficial to those who have to make frequent overseas contact or have high call volumes as the cost per call is low when it is over the internet rather than over dedicated telephone lines.
• Large corporations that require collaboration with multiple people can utilize VoIP since the rate is the same for a single connection as well as a multiple connection.
There are a few issues that prevent general acceptance of VoIP.
• There is a lack of transmission quality during periods of high network congestion. When the bandwidth is limited and network congestion occur IP packets are dropped. This results in poor voice quality and even loss of connection.
• If the network goes down then all means of communication both voice and data is cut off. This results in the reluctance to change over to VoIP
• Calls to emergency services are not yet provided by VoIP. The situation may change as this has been made mandatory by the government.
• There are no directory listings or yellow page listings for VoIP numbers.
What ever the bold promises VoIP offers if it does not deliver on the internet scene it still is an advantage on the intranet scene.