"The Great Voice Myth" states that there is only one way to build voice networks and that there should be only one voice protocol for each function in a packet voice network. Although this vision of network nirvana has been discussed in many academic circles, the reality is that multiple VoIP protocols and architectures have already been deployed, they will exist for the foreseeable future, and many networks will continue to be built using multiple VoIP protocols.

Just as today's data networks were built over time using multiple protocols and applications, the VoIP networks of today and tomorrow will be constructed using the protocols and applications that best fit the associated technology and business requirements.

The question that companies must ask is not "Which protocol is best?" but "Which services do we want to deploy, and which VoIP protocols best support those services?" The answer to the first question may reflect the bias of a particular vendor or standards body. The answer to the second question depends entirely on the unique requirements of each network implementation. Because no two businesses or networks are exactly the same, each company will answer the second question in its own way.