While implementation issues often fade as technologies mature, Voice and Video over IP may be experiencing the exact opposite condition. Quickly evolving Codec requirements and specifications, along with a growing universe of a diverse set of endpoints that may or may not be 100% compliant with these standards, may make it more difficult to offer voice and video services in a consistent manner to all endpoints. In a time when phone calls must often traverse multiple networks, and in which different networks often support different codecs and protocols, transcoding voice and video sessions between various networks and end-point devices is increasingly necessary.

The desire to provide mufti-party voice and video conferencing highlights this problem even further, as every endpoint in a mult-party session may be using a different codec. Real time transcoding becomes the only way to manage the complexity of this every increasing problem.

This survey is designed to help us understand the impact of existence of disparate endpoints and the need for real time transcoding to both the enterprise and the service provider.