SONiC Software Architecture for Smart Switch

This section describes the SONiC software architecture for the Smart Switch (Cisco 8102-28FH-DPU-O router).

The Cisco 8102-28FH-DPU-O router is a first-generation Smart Switch equipped with the Cisco Silicon One Q200L switching processor and an AMD DSC-200 Data Processing Unit (DPU), all housed in a two-rack unit form factor. It offers a total network bandwidth of 12.8 Tbps, which includes 11.2 Tbps for switching and 1.6 Tbps for DPU processing, and it contains 28 QSFP-DD 400 Gigabit Ethernet (GbE) ports.

A SONiC DPU is a processing unit used to offload and accelerate various data processing tasks.

The Network Processing Unit (NPU) of the Smart Switch operates with the open-source network operating system SONiC (Software for Open Networking), while the DPU modules run the Disaggregated API for SONiC Hosts (DASH).

Disaggregated API for SONiC Hosts (DASH)

The Disaggregated API for SONiC Hosts (DASH) is an extension of the traditional SONiC architecture. DASH enhances SONiC by enabling disaggregation of networking functions, allowing for more flexible and scalable network management. DASH builds upon the existing SONiC framework by introducing additional functionalities, such as:

• Support for DPU modules: DASH is designed to work with DPU modules, which offload and accelerate various data processing tasks from the main CPU.
• Extended API Support: It uses a combination of traditional Switch Abstraction Interface (SAI) headers and new DASH pipeline-specific extension headers to support a broader range of networking operations.
• SDN Control Plane: DASH adds a new Software-Defined Networking (SDN) control plane through the gRPC Network Management Interface (gNMI), which facilitates more efficient network management and configuration within the DASH container.

This image illustrates the SONiC DASH architecture on the Smart Switch.

Smart Switch software components

This image illustrates the key components of Smart Switch Software.

These are key components of Smart Switch Software:

• Data Processing Unit (DPU) with SONiC:

  • DASH/SONiC Lite: Tailored as a minimal version of SONiC for DPU modules, designed to fit the limited footprint using one to two cores.
  • SAI-DASH Integration: Facilitates efficient configuration and management communication between DPU modules and the SONiC ecosystem through an abstraction interface.
  • Polaris Container with PDS Agent: Manages data flow and processing within the DPU architecture.

• DASH (Disaggregated API for SONiC Hosts):

  • SAI-DASH Interface: Extends the traditional SAI interface with DASH-specific headers, optimizing it for DASH scenarios.
  • SDN Controller: Manages the DASH overlay services and controls the overlay built on the physical layer (underlay) of the infrastructure, while SONiC application containers manage the underlay (L3 routing) and hardware platform.
  • gNMI Container: Enables communication between the SDN controller and a DASH device through a gNMI endpoint, served by a new DASH SDN agent within a SONiC DASH container.
  • Service Manager: Operates on the host CPU as an SDN agent, efficiently distributing configurations to DPU modules via ZMQ.

• Telemetry and Monitoring:

  • PMON Functionality: Ensures comprehensive local state monitoring on DPU modules, with data aggregated by Switch SONiC for a unified view.
  • Telemetry: Consolidates and exports data from each DPU for analysis and management.

• Configuration and Data Management:

  • Centralized Management: Maintains all configurations for NPUs and DPU modules using databases like ASIC_DB on the switch CPU.
  • Memory Management: Stores configuration data on the host CPU to optimize limited DPU memory and ensure efficient retrieval during warm boot.

• DPU Lifecycle Management:

  • Lifecycle Control: Ensures updates and configurations are coordinated across the network, managed by Switch-SONiC.

Benefits of the DPU Integration with Smart Switch

Integrating DPU modules with Smart switches in the SONiC architecture offers several benefits:

• Enhanced Performance: DPU modules offload processing tasks from the main CPU, allowing for higher throughput and reduced latency in network operations. This capability leads to improved overall network performance and efficiency.

• Improved Scalability: DPU modules enable better scalability by efficiently managing and distributing workloads. This is particularly beneficial in large-scale network environments where demand and data flow are continuously increasing.

• Advanced Telemetry and Monitoring: With comprehensive telemetry and monitoring capabilities, network administrators can gain deeper insights into network performance and health. The aggregated data from DPU modules allows for more accurate analysis and better decision-making.

• Centralized and Efficient Configuration Management: The centralized management of configurations by Switch-SONiC simplifies the process of updating and maintaining network settings. This process ensures consistency and reduces the risk of configuration errors.

• Optimized Memory Usage: The architecture optimizes the limited memory available on DPU modules by storing configuration data on the host CPU. This efficient memory management is crucial for maintaining high performance and reliability during network operations.

What to do next: To install Install SONiC on Smart Switch.