Session routing proxy

Our session routing proxy (SRP)—the Net-Net Session Router (SR)—overcomes the challenges inherent in routing large numbers of SIP-based voice, video, instant messaging and multimedia sessions within service provider mobile, fixed line and transit networks.

Session routing proxies address scaling problems when session routing decisions become much more complex, requiring a dynamic, real-time routing decision for each individual session for multiple sources and destinations within a network. These source and destinations are other SIP signaling elements such as session border controllers, Mobile Switching Centers (MSC), IMS subscriber call control elements and softswitches controlling media gateways.

Provisioning routing information and control in each of these SIP elements is extremely expensive and error-prone. Enabling each element to make routing decisions also increases capital costs, since additional hardware processing is required by each element. The use of an SRP centralizes and consolidates routing control, reducing costs. Since the source and destination SIP signaling elements are session-stateful, an SRP can operate in a transaction-stateful mode, maximizing routing performance. The SRP can also operate in session-stateful mode when protocol normalization, accounting or other stateful functions are required.

Because the routing table size needed to support SIP-based services can be massive, session routing proxies are capable of using both internal and external routing databases. Internal routing databases best support static, localized routing decisions for up to a few million routes. Routing rules that are extremely dynamic, global or exceed a few million routes are best supported using the high-capacity, centralized external databases.

The Net-Net SR plays a central role in our Open Session Routing (OSR) architecture. This solution provides tremendous deployment flexibility and facilitates network evolution from small to large numbers of border points and from PSTN to IP network-focused connectivity. It uses industry-standard ENUM, SIP, XML or DNS protocols to leverage both internal and external best-of-breed routing products and services from Acme Packet’s OSR partners The Net-Net SR configuration is supported on our hardware platforms—the Net-Net 3820, 4500 and 9200. It leverages our Net-Net OS software platform to offer industry-leading routing proxy capabilities in terms of SIP routing performance, routing control and deployment options, openness and interoperability, high availability and cost-effectiveness.