In this section:
The Distributed SBC (D-SBC) solution distributes the core SBC components (signaling, media and transcoding) into discrete functional elements that allow the SWe instance to instantiate and scale the components independently in their own respective clusters. This is ideal for greenfield (initial) deployments where all the three clusters are deployed; however, in an existing network, D-SBC uses the services of an external transcoder for audio transcoding.
In the D-SBC architecture, the virtualized Signaling SBC (S-SBC) and Media SBC (M-SBC) instances support signaling and media relay functionalities. The Media Resource Function (MRF) supports any media inter-working requirement that includes transcoding and transrating1. The S-SBC invokes the MRF using a 3PCC call model.
Media Resource Function – Resource Manager (MRF-RM) runs on the SBC and interacts with external third-party transcoder (MRF Server) to provide transcoding services. The S-SBC manages the transcoding resources on MRF server remotely using SIP interface. Any third-party transcoder that supports SIP interface is used as MRF server within the SBC to provide Audio transcoding services.
For the D-SBC on OpenStack, the SBC only sends a COMMIT INVITE
to the MRF server – it does not send a RESERVE INVITE
to the MRF (Reactive mode, enabled by default).
Signaling IP/Port information
Local/Remote End Point information for both Ingress and Egress private leg towards MRF
For more information on CLI changes, refer to D-SBC Cluster - CLI.
1 The process by which video and audio files are converted to a reduced bit rate while still maintaining the original media format.