Distributed Gateway Routers for SD-WAN Scaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing routing solutions for SASE-enabled destinations face challenges in large-scale deployments due to limitations on the number of edges that can connect to a transit point or gateway router, leading to issues like end-to-end visibility loss and constrained hierarchical deployments.
Innovation Solution
The implementation of distributed, disjoint gateway routers supports multi-hop routing, enabling branch-to-branch VPN, customizable VPN profiles, seamless switching between redundant transit points, and full-mesh or customizable mesh configurations for redundancy and resiliency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a common controller model is used for route propagation, then route exchange is simplified, but the number of edges that can connect to a transit point is limited
Solution Approach 1:
The patent divides the single common controller into multiple distributed gateway routers, each serving as a transit point for specific regions. This segmentation allows edges to connect to local gateway routers rather than a single centralized controller, increasing the total number of edges that can be supported while maintaining simplified route exchange through regional gateways.
2Adaptability or versatility
If overlay routing is used for branch-to-branch connectivity, then routing flexibility is improved, but end-to-end visibility is lost during overlay-to-underlay handoffs
Solution Approach 1:
The patent implements feedback mechanisms where gateway routers propagate reachability information and routing context back through the overlay network. This allows edges to receive feedback about the original sender's information and underlay path details, maintaining end-to-end visibility while preserving overlay routing flexibility for branch-to-branch connectivity.
3Ease of manufacture
If a common gateway model is used, then deployment simplicity is maintained, but manual assignment of controllers is required to manage edge connections
Solution Approach 1:
The patent enables edges to autonomously select and connect to appropriate gateway routers based on local policies and network conditions. This self-service capability eliminates the need for manual controller assignment while maintaining deployment simplicity, as edges automatically establish connections to the most suitable transit points without requiring centralized manual configuration.
4Quantity of substance
If hierarchical deployments are implemented, then scalability is improved, but the maximum supported overlay hops is limited to two
Solution Approach 1:
The patent implements dynamic routing where gateway routers can be dynamically selected and reselected based on network conditions, policy changes, and availability. This dynamic capability allows hierarchical deployments to support more than two overlay hops by enabling edges to route through multiple gateway routers in sequence, with each gateway dynamically establishing connections to the next hop in the hierarchy.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Some embodiments of the invention provide a method for implementing an SD-WAN connecting multiple sites at multiple physical locations. The method is performed at a first hub router of the SD-WAN. The method establishes, with a first edge router of a first site in a first region, a new connection for the first hub router to use to connect the first edge router to a second edge router of a second site in the first region. The method determines that a peer-connection notification regarding the newly connected first edge router has to be sent to a first route reflector (RR) that does not connect directly with the first edge router but connects to routers in a second region. The method sends the peer-connection notification to the first RR to analyze and determine whether to obtain routes associated with the first edge router for advertising to routers in the second region.