Introduction

The Cisco SMF has a three-tier architecture consisting of Protocol, Service, and Session tiers. Each tier includes a set of microservices (pods) for a specific functionality. Within these tiers, there exists a Kubernetes Cluster comprising of Kubernetes (K8s) master, and worker nodes (including Operation and Management nodes).

For high availability and fault tolerance, a minimum of two K8s worker nodes are required for each tier. You can have multiple replicas for each worker node. Kubernetes orchestrates the pods using the StatefulSets controller. The pods require a minimum of two replicas for fault tolerance.

SMF Architecture

The following figure depicts an SMF K8s Cluster with 12 nodes – three Master nodes, three Operations and Management (OAM) worker nodes, two Protocol worker nodes, two Service worker nodes, and two Session (data store) worker nodes.

SMF Kubernetes Cluster
Note
  • OAM worker nodes: These nodes host the Ops Center pods for configuration management and metrics pods for statistics and Key Performance Indicators (KPIs).

  • Protocol worker nodes: These nodes host the SMF protocol-related pods for service-based interfaces (N11, N7, N10, N40, NRF) and UDP-based protocol interfaces (N4, S5/S8).

  • Service worker nodes: These nodes host the SMF application-related pods that perform session management processing.

  • Session worker nodes: These nodes host the database-related pods that store subscriber session data.