Sonus Networks pioneered the concept of centralized SIP policy management with its PSX™ Centralized Policy and Routing Server. The PSX quickly become the gold standard of SIP policy management, and today drives millions of SIP sessions in the world’s communications networks every hour. The PSX platform offers an open, advanced SIP routing and policy server that manages SIP-based policies across the entire network including media gateways, softswitches, session border controllers and mobile switching centers, and which can be easily extended through software modules to address unique SIP policy roles such as least cost and value-based routing, hosted number portability and IP Multimedia Subsystem (IMS) Breakout Gateway Control Function (BGCF).
Typical deployment examples of the PSX Server include:
- NGN, IP Interconnect or Cable networks with disparate multi-vendor gateways and SBCs, where the PSX Server unifies and provides centralized management of the entire network;
- IMS network as a BGCF;
- IPX or IP Interconnect network as a centralized policy management and routing server;
- NGN or IP Interconnect network as a Number Translation Server;
- IPX or IP Interconnect network as a Least Cost Routing (LCR) server.
The PSX Server addresses some of the most important challenges facing SIP networks:
- Scalability in the number of policy and routing decisions that can be performed as the amount of SIP sessions increases in the network;
- Interworking between a wide range of internal and external network devices that speak different signaling languages including IPv4 and IPv6, legacy PSTN protocols (e.g., ISUP, H.248) and the many varieties of SIP favored by network solution vendors;
- Simplicity in the management and provisioning of network-wide policy and routing information including MACs (Moves/Adds/Changes), overload controls, least cost routes and number portability lookups;
- Ability to seamlessly migrate/upgrade existing policy servers to address new challenges such as Unified Communications, IP Multimedia Subsystem (IMS) interoperability and hosted number portability services.
