Fault-tolerant AAA HSS/DIAMETER Services across
IMS Framework

Authentication through DIAMETER is emerging as a critical component of carrier access authentication schemes for IMS frameworks. DIAMETER service failures and service disruptions immediately translate into subscriber disconnection, negatively impacting carrier customer retention and increasing churn. Carrier DIAMETER service processing includes the handling of a large volume of requests from across the Cx (x-CSCF) and Sh (SIP-AS and OSA-SCS) reference interfaces (3GPP reference architecture) forming the basis for fixed/mobile convergence (FMC).

DIAMETER service continuity, optimization and scalability require the ability to go beyond TCP session distribution to manage DIAMETER message-level load distribution.

DIAMETER key service challenges include

• DIAMETER Availability – Fault-tolerant DIAMETER server and service operations are needed to ensure message processing for various network services
  
  
• DIAMETER Scalability – Carriers require the ability to effectively scale DIAMETER services to meet a growing number of service requests across Call Session Control Function (x-CSCF), service switches (Cx) as well from SIP application servers (Sh). As proxy and service CSCF servers manage call/session set-up, modifications and releases, they exhibit high signal volumes and a large number of RADIUS requests, creating service congestions that can negatively impact service experience
  
  
• DIAMETER Infrastructure Consolidation – Carriers seeking to reduce the complexity and cost of AAA services must be able to consolidate DIAMETER servers and centrally manage distributed architectures