Traditionally, a phone conversation is converted into electronic signals that traverse an elaborate network of switches, in a dedicated circuit that lasts the duration of a call. In Voice over Internet Protocol, a conversation is converted to packets of data that flit all over the Internet or private networks, just like e-mails or Web pages, though voice packets get priority status. The packets get reassembled and converted to sound on the other end of the call.
Early VoIP services often sounded tinny, delayed or digitized. In recent years, the technology has gotten much better, and Guzman & Co. analyst Pat Comack said it won't be long before it achieves the tech industry's vaunted "five 9s" level -- 99.999 percent reliability. For now, VoIP may not be perfect, but cell phones have made people more accepting of less-than-ideal sonic conditions.
A broadband Internet connection. You can use a regular phone, as long as you connect it to an adapter. However, companies such as Cisco Systems Inc. now make VoIP phones that don't require adapters. The adapter or new VoIP phone connects to a broadband modem. Some VoIP providers can link to an entire home's wiring so adapters aren't required at each extension.
The biggest disadvantage is that currently all VoIP providers to not offer emergency 911 service in all areas. The FCC has recently ruled though that this is a mandatory requirement that must be completed by September 2005.
Generally following things are required for voip
1. Broadband connection
2. voip phone
3. nexton softswitches
6. astric server