IP telephony, while still relatively new, is poised to revolutionize corporate telecommunications by at last enabling users to haul voice and data traffic over a single wide area network. International Data Corporation, predicts that the Internet telephony market will grow from US $3.5 million in 1995, to US $560 million 1999. Meanwhile, Tarifica in the UK estimates that AT&T will to lose between US $620 million and US $950 million in international calls to the Internet by 2001. The problems with telephone systems as they are today, are getting increasingly higher for long distance phone class. Imagine even local ISP's (Internet Service Providers) offering such low rates as $.02 a minute phone calls from Rapid City to Sioux Falls.The idea behind IP telephony is enticingly simple, convert voice into packets for transmission over a company's TCP/IP network. Although simple in principle, IP telephony presents some tough technical hurdles for vendors to surpass. This report will provide readers with a comparative analysis of the IP telephony products currently on the market, or scheduled to ship that will help you understand the significance of incorporating this technology for the benefit of the consumers. IntroductionThe basic concept behind IP telephony is deceptively simple: convert voice into a series of packets, and transmit them across an IP network to be reassembled on the receiving end. While theoretically simple, IP telephony designers face a number of technical challenges, many of them similar to those encountered in designing a digital cellular network. These challenges make designing a good IP telephony gateway a significant undertaking. Vendors have approached IP telephony from several different angles. Some vendors have leveraged existing hardware such as Dialogic's multi-port voice cards in conjunction with their own software. Other vendors have built their own DSP cards designed specifically for this task. Other ven...
