13.1 Introduction

Voice is an integral element of many of the emerging breed of conversational IP applications found on the Internet. This chapter examines the opportunities to provide these types of application at scale, and considers some of the difficulties in translating what may be interesting toys on the lab bench into genuinely useful public-scale communication services. It characterises early VoIP network service solutions, charting their evolution towards contemporary services and considers some of the types of application that may be possible in the future.

The long-term promise of IP is to provide a coherent infrastructure on which to offer a plethora of multimedia services including voice. Voice over IP, and more specifically voice over the Internet, as described in Chapter 1, has been seen as a major threat to the revenues of existing voice service providers by enabling business opportunities for new entrants to the voice transport market by exploiting regulatory arbitrage between voice and data services. This has been coupled with the perception of many end users that telephone calls will be 'free' over the Internet. However, the definition of 'free' needs to be carefully examined and has largely been exposed as a fallacy in the market. In the UK, Internet service provider (ISP) fees are usually either absorbed within communication service charges and so appear to the end user as metered phone calls, or provided as a flat rate service. Conversely in the USA,...