Pragmatic Approaches to True Convergence with or without IMS

This paper presents lessons learned from trying to address the questions of operators or communications service providers in general who try to take advantage of NGNs (next generation networks) to provide attractive and revenue generating new multimedia and/or converged services. IMS (IP Multimedia Subsystem) is often presented as the ideal solution for operators to achieve these objectives. However recently adoption of the IMS has slowed down as more and more questions about business viability are raised. In this paper we illustrate how the same objectives as what initially motivated the design or deployments plans of the IMS can be achieved with a pragmatic incremental approach that may be more business viable while at the same time allowing service providers to offer immediately IMS like services. This paper also introduces a definition for SDP (service delivery platform) and positions it with respect to IMS or NGNs. In particular we illustrate that the notion of convergence is totally decoupled from the IMS: it does not mandate the IMS and when doing so, it can in fact generalized the notions way beyond what is today seen as example of convergence. As a result we propose a pragmatic approach to target deployment of IMS-like multimedia services, IP communications networks and convergence that we believe is business viable and will facilitate adoption of IMS whenever it makes sense; while at the same time not mandating IMS..