The document summarizes the results of a test between HP and Amdocs to prove the interoperability of their IMS billing systems. The test involved using HP's charging manager and Amdocs' billing system to successfully process VoIP calls using the Diameter protocol. This demonstrated that a charging system and billing system can be integrated into the IMS architecture using standards-based approaches. Several major service providers had already deployed successful IMS-compliant services using real-time charging capabilities.

1. HP and Amdocs Prove IMS Billing Interoperability Nigel Upton, HP BSS Products General Manager March 14, 2008