In the past couple of years, IMS has become one of the biggest buzzwords in the telecom industry because of its promise of enabling operators to roll out a multiplicity of new services rapidly and inexpensively even while cutting costs by consolidating networks, back office systems, and staff.

Far less fuss has been made of IMS’s bigger brother, Tispan, which incorporates IMS (IP Multimedia Subsystem) but actually does a whole lot more by tackling many of the specific requirements of fixed networks.

In a nutshell, Tispan tackles non-SIP applications and IMS doesn't – and that's a very big deal. Why? Because non-SIP applications include not only legacy services but also HTTP applications and peer-to-peer file sharing. In other words, they represent a substantial proportion of traffic on current and future IP next-generation networks (NGNs).

This realization is now triggering growing interest in the European Telecommunications Standards Institute (ETSI)’s Tispan NGN standard, particularly since the publication in December 2005 of Release 1. Many telcos and service providers are beginning to specify – or are planning to specify – Tispan in their NGN rollouts, so Tispan is by no means just another vendor-inspired bandwagon.

Indeed, a poll taken during the Webinar on which this report is based suggests that Tispan is hitting the right buttons on current concerns over NGN services. Nearly 45 percent of respondents believed that the first service deployed on a Tispan RACS/NASS subsystem would be PSTN emulation, followed by 33 percent who favored converged fixed/mobile multimedia SIP-based services.

NGNs are increasingly seen as important tools in the future profitability of network and service providers. They are about network convergence and a common service portfolio, regardless of access mechanism. For its proponents, Tispan delivers the architecture on which NGNs will be based, at least initially. And it’s not just about advanced services over a converged network – it’s crucial to service providers being able to scale their application delivery processes.

Today, the network is the service. Tomorrow, the service is an individual application, and the network is merely the transport that needs to be controlled to support the application. Supporting this potentially huge diversification of the service provider and telco product portfolio requires an architecture and framework above and beyond the basic network for accelerating the delivery and management of applications. Tispan is a step along the path to achieving this.

It is thus increasingly important to understand what Tispan is, what it isn’t, what it can do now, and what it is going to be able to do in the future should all the planned extensions materialize. Here’s a hyperlinked contents list into the Tispan maze: