What is used by vManage to interact withCiscoSD-WAN devices in the fabric?

In the context of Software-Defined Networking (SDN) architecture, which Cisco SD-WAN is based on, communication interfaces are categorized as northbound or southbound. vManage, acting as the management plane controller, communicates "down" to the network devices in the fabric (vSmart, vBond, and WAN Edge routers) to push configurations, policies, and retrieve operational data. This interface between the controller (vManage) and the network infrastructure is defined as the Southbound API. It allows the management system to program and manage the underlying network elements.

A. northbound API: A northbound API is used by external applications and orchestration systems to interact with vManage, not for vManage to interact with the fabric devices.

B. RESTCONF: RESTCONF is a specific protocol, typically used for northbound APIs, that provides a programmatic interface over HTTP for accessing data defined in YANG. It is not the general term for the interface vManage uses to manage fabric devices.

D. IPsec: IPsec is a protocol suite used to secure the data plane tunnels between WAN Edge routers. It is not used for the management and control plane communication between vManage and other fabric components.

1. Cisco Systems

"Cisco SD-WAN Design Guide" (July 20

2022). In the "Cisco SD-WAN Components" section

the guide describes vManage's role: "The vManage NMS is a centralized network management system that lets you configure and manage the entire Cisco SD-WAN overlay network from a graphical user interface." This function of a centralized controller managing network devices is the definition of a southbound interface's role. The guide also explicitly details the "Northbound API" for integration with external systems

clearly distinguishing it from the southbound function. (Reference: Chapter 1

"Cisco SD-WAN Architecture

" Section: "Cisco SD-WAN Components").

2. Haleplidis

E.

et al. "Software-Defined Networking (SDN): Layers and Architecture Terminology." RFC 7426

IETF

Jan. 2015. This informational RFC defines the standard terminology for SDN architecture. Section 4.2

"Southbound Interface (SBI)

" states

"The Southbound Interface is the interface between the SDN Controller and the SDN Datapath... It allows the SDN Controller to make demands on the datapaths

and the datapaths to make the controller aware of their capabilities." This directly maps to the interaction between vManage (Controller) and the SD-WAN devices (Datapaths). (DOI: https://doi.org/10.17487/RFC7426).

3. Cisco Systems

"Cisco SD-WAN Controller Certificates and Authorization." This document describes the secure communication channels between controllers. It states

"The Cisco vManage server and the vSmart controller authenticate each other through certificates and establish a secure DTLS/TLS connection." This secure connection is the transport for the southbound communication

which carries management and control information

distinct from data plane IPsec tunnels. (Reference: Section "Control Plane Connections").