Open session routing (OSR) architecture

Our Open Session Routing (OSR) architecture features the use of our SRPs working in conjunction with a world-class ecosystem of routing database products and services from our partners.

These complementary product vendors and service providers offer centralized routing databases and database provisioning tools for dynamic route selection. Our Net-Net SR—as well as the Net-Net Session Director (SD)—queries these centralized databases using industry-standard ENUM, SIP and DNS protocols. The Net-Net SR’s local route tables can also be provisioned by third-party tools or via Acme Packet's Net-Net Central Route Manager application. Using these databases, dynamic routing decisions within the core IP network and to the PSTN and other IP networks can be made using a wide selection of parameters.

The powerful combination of our SRP and our partner ecosystem results in extremely fast session routing performance and increased network capacity, as well as lower overall network costs when compared to a solution in which the routing function is distributed among several SIP elements.

OSR addresses scaling problems when SIP session routing decisions become overly complex, requiring a dynamic, real-time routing decision for each individual session for multiple sources and destinations within a network. These source/destinations are other SIP signaling elements such as:

Fixed line access network borders

  • CLASS 5 softswitches and Cable Modem Termination Systems (CMTS) connecting residential and business subscribers over any type of fixed line access network including DSL, cable, Ethernet, FTTx, leased lines
  • SBCs connecting large enterprises and contact centers over SIP trunks

Mobile access network borders

  • Mobile Switching Centers (MSCs) connecting TDM-based 2G/3G radio access networks
  • MSCs or SBC/Multiservice Security Gateways (MSGs) connecting the Internet to femtocell and WiFi access points for UMA or SIP services
  • SBCs connecting IP-based 3G/4G radio access networks

IMS service core access

  • IMS core elements connecting to access networks and interconnect networks

Interconnects/peering borders for wireless and wireline networks

  • SBCs connecting external service provider-managed IP networks or the Internet
  • CLASS 4 softswitches and media gateways connecting to the PSTN

Core Routing Diagram