SD-WAN Terminology Lecture Notes

Introduction

• Focus on important terminology related to SD-WAN.
• Key terms include: T-Lock, OMP, color.

SD-WAN Controllers

• Three main controllers in SD-WAN:
  • vManage: Management plane.
  • vSmart: Control plane, brain of the SD-WAN.
  • vBond: Orchestration plane.
• WAN Edge (WANH): Data plane in SD-WAN.

Types of Connections

• Control Connections: Secure connections between controllers and WAN Edges.
  • Example: Control connection over DTLS between vBond and vSmart.
• Data Connections: IPSec connections for end-to-end communication between WAN Edges.
  • Example: Secure connections between vManage and WAN Edges.

Connection Types Overview

• Control connections:
  • vBond to vSmart (DTLS)
  • vBond to vManage (DTLS)
  • vManage to vSmart (DTLS)
• Data connections:
  • WAN Edges communicate over IPSec.

SD-WAN Components

• vManage: Software-based only (VM).
• vSmart: Software-based only (VM).
• vBond: Software-based only (VM).
• WAN Edge: Can be either software (VM) or hardware appliance.

Overlay Management Protocol (OMP)

• OMP is used for:
  • Routing
  • Policy advertisement
  • Key exchange
• OMP operates over secure connections (DTLS/TLS) between VSmart and WAN Edges.
• OMP functions similarly to BGP in traditional routing.

OMP Neighborship

• Automatically established when a secure connection (DTLS/TLS) is made between WAN Edges and VSmart.
• Identifiers for OMP neighbors are based on System IP (unique identifier for devices).

System IP

• Unique identifier for every SD-WAN device (e.g., vSmart, vManage, WAN Edges).
• Example: System IPs can be 1111, 11110, 11120, etc.

Routing with OMP

• OMP facilitates routing by allowing WAN Edges to send their routes to VSmart, which acts as the route repository.
• WAN Edges advertise their connected routes to VSmart using OMP.

T-Lock (Transport Location)

• T-Lock is a unique identifier for a circuit in SD-WAN, similar to next hop in BGP.
• T-Lock includes:
  • System IP
  • Color (to uniquely identify T-Locks)
  • Encapsulation (IPsec or GRE)

Colors and Encapsulation

• Color: Helps create unique identifiers for T-Locks. It can be public or private.
• Encapsulation: Determines the type of connection security (IPsec recommended over GRE).

Data Plane Encapsulation Types

• IPsec: Provides security (authentication, encryption).
• GRE: No security features.

Summary of Routing in SD-WAN

• WAN Edges send their routes to VSmart using OMP.
• VSmart redistributes the routes to other WAN Edges.
• OMP is proprietary and only functions within the SD-WAN overlay.
• Redistribution of external routes (e.g., from OSPF, EIGRP) into OMP and vice versa is possible.

Redundancy and Load Sharing

• Multiple VSmart instances can be deployed for redundancy.
• In the event of receiving routes from multiple VSmart instances, a WAN Edge selects the route from the VSmart with the lower system IP.

Conclusion

• Understanding of SD-WAN routing and components is important for implementation.
• Further videos will provide more insights into these topics along with practical scenarios.