2004

VoIP (Voice Over IP or Voice Over Internet)
By Pawas Verma

Voice over Internet Protocol (VoIP) is a multimedia technology where the broadband network is used for both voice and Internet transmission. This allows people to make cheap voice calls over a high-speed Internet connection using a special "IP" phone or a conventional phone-set attached to an adapter. The advantage of this technology is that the voice communications can ride along with Internet and other broadband traffic without impacting too much on the capacity of the network or the cost of providing services.

The bandwidth occupied by a voice message is a tiny fraction (0.3% of a DSL connection to a residence OR 0.003% of a business connection) of the total bandwidth of a connection. First, voice (in analogue form) is digitized, coded and arranged into small information packets. These packets (packages) are then mixed and multiplexed with packets of other information traffic like Internet, data and video before transmitting to a distant location. Each information packet has its own identification (Header and Destination bits). The destination bits guide these packets on the network to a correct destination and the "Header Bits" allow them to be identified, separated and regrouped to pass through a decoder. The output of the decoder is filtered and amplified to regenerate the original voice at the receiving end.

It is a great development from users viewpoint. A VoIP user can continue to use his/her current telephone number or get a new VoIP number. The telephone number is not fixed to one location. The telephone set and the telephone number can move with the user. People can reach a person even if he or she is not at its location. Similarly, a person can call on their phone from anywhere in the world (in approved areas/regions) without incurring long distance charges. For a fixed monthly fee, VoIP service allows limited or unlimited local and long distance calling. For example, one of the biggest North American VOIP companies - "Vonage", under its basic residential plan charges $19.95 per month for 500 minutes of local and long distance calling. Primus Canada charges $14.95 for local residential services which is lower than $25 - $35 per month charged by a telephone company (based on a conventional telephone network ) for similar services. One can also have local telephone numbers at different locations (theoretically) in the same or different countries. In such cases, the area codes could be either the existing ones or IP assigned area codes. A few Canadian cable and telephone companies (Telus, Bell Canada, etc.) have started providing VoIP services.