Introduction

Intelligent Networks were designed in the early 1990s for delivering value added services in  circuit switched telephony networks.  At that time the World Wide Web was still in its infancy and in many countries a single national operator still owned the network.  Deregulation forced many operators to open up their networks to third party services; however Intelligent Networks were not originally designed to allow external access to its interfaces.  OSA and Parlay have evolved from Intelligent Networks as an answer to this problem, and are seen by many as their natural succesor. 

Parlay and OSA specify the interfaces that allow third party applications to control network functions and respond to network events.  These interfaces are open, language and platform independent, and include security features.

Parlay or OSA?

Parlay was born in 1998 as an initiative of BT (UK's incumbent operator), Microsoft, Nortel, Siemens and Ulticom to provide third party access to basic network functions, allowing third parties to create and deploy value added services for the telephony network.

Around the same time, 3GPP (3rd Generation Partnership Project) was in the process of defining a general architecture for its "virtual home environment", the portable service concept for UMTS.  It wasn't long before the Parlay Group and 3GPP realized that they were on the same track.  3GPP used the Parlay specifications as the starting point for its Open Service Access (OSA) specifications, and in 2001 the two groups decided to completely align their standards.  There is now one set of specifications that is available from both the 3GPP and Parlay web sites.  In the remainder of this tutorial we'll simply refer to OSA-Parlay as one standard.

 Research