The importance of interoperability monitoring and testing for IMS

IMS has been hailed as the unifying architecture for disparate access technologies and a panacea for crippling vendor interoperability issues.  But the reality is different: IMS creates an intricate, hard-to manage architecture based on standards which are in constant flux.

While interoperability is a core value, this situation makes it exceptionally hard to get vendors from diverse backgrounds and with conflicting commercial interests to interwork.

Chad Hart, Product Marketing Manager at Empirix, a US based testing, monitoring and performance solutions provider, believes that complexity and standards ambiguity are the greatest challenges for the true realisation of IMS. "The complexity of the IMS architecture is the main obstacle to real deployment together with standards ambiguity, even though the industry has come a long way in the last 2 to 3 years. On one hand we see consolidation with the operational convergence between 3GPP/3GPP2 and ETSI TISPAN but, on the other hand, standards are not always clear. For example, if we look at the status with VCC for fixed mobile convergence, it is clear that we don't really have a standardised blueprint on how to build an FMC network."

A considerable amount of testing activity has been recently conducted and initiatives such as the IMS Forum Plugfest and the Global MSF (MultiService Forum) Interoperability events (GMI) have been particularly successful. GMI for instance is focusing  on providing a technical validation of the MSF Release 4 Architecture and supporting implementation agreements as the basis for interoperability between vendors within practical network deployments.  

If testing and monitoring was not much of a concern in the early days, the tough reality of real world IMS implementation has put a renewed focus on equipment interoperability testing in recent years and as more operators move to live IMS networks, either partially or completely, network monitoring is the next challenge.  

What's more, compared to traditional network monitoring, it no longer suffices to take an "island" approach because IMS joins together every aspect of the network from services all the way down to individual network elements. In this context it is fundamental to apply a holistic approach that takes the entire operation into account. 

"The industry is clearly moving form the hype phase and theoretical approach to IMS to real life implementation. In a practical framework effective monitoring and testing are essential" says Hart. "As a market leader in NGN testing and monitoring, Empirix works with vendors and service providers, testing IMS core network equipment in the lab and monitoring IMS networks after deployment. We can therefore offer great insight into the challenges IMS faces in the real world and how they can be addressed."

"We believe that there is a strong business case for a lifecycle testing and monitoring strategy, from testing networks in the pre-production phase all the way to monitoring service quality in the life network to meet SLAs and regulatory quality requirements", concludes Hart. "It is fundamental to designing IMS tests and select the right tools. Monitoring strategies should always be devised early on in the rollout, even if you are starting small."