The CUPS User Plane (UP) is an all-important network component in the core network that carries and anchors the data traffic of subscribers. To ensure a smooth quality of experience (QoE), it is necessary to preserve data traffic and continue with minimal interruption. This is feasible only when there is a provision of a robust redundancy mechanism for all the data sessions that are hosted and anchored on UPs.

Every UP should have a redundant UP on standby (warm, hot, or active). However, this model mandates significant resource requirement for the service providers and is not a preferred model because of the number of UPs that can keep scaling horizontally. The preferred model is to have an N:M model with multiple UPs acting as standby-UPs for every active UPs. The N:M Redundancy feature provides this redundancy model.

On the UP, there is a new Cisco proprietary node called the Redundancy and Configuration Manager (RCM) which handles the configuration management of the UPs and the redundancy functionality.

For details on N:M redundancy and RCM, refer the Redundancy and Configuration Manager Configuration and Administration Guide.