In SD-WAN topology, which statement best describes hub-and-spoke versus partial-mesh topology?

• A. Hub-and-Spoke funnels traffic through central hubs; partial mesh enables direct site-to-site tunnels.
• B. Partial Mesh funnels traffic through central hubs; hub-and-spoke enables direct site-to-site tunnels.
• C. Full mesh requires a central hub for all intersite traffic.
• D. Hub-and-spoke and partial-mesh are identical in traffic patterns.

Answer: (A)

In SD-WAN topology, the way intersite traffic is routed is what sets hub-and-spoke apart from partial mesh. In a hub-and-spoke design, remote sites (spokes) connect to central hubs, and traffic between two spoke sites typically travels through the hub unless a direct tunnel is specifically configured. This centralization simplifies policy enforcement and security, but can add latency for spoke-to-spoke traffic if there isn’t a direct path.

Partial-mesh offers a middle ground by allowing some direct site-to-site tunnels between certain sites. That means traffic for those pairs can go directly, bypassing the hub, while other pairs may still route through the hub. This setup provides reduced latency and improved performance for critical site pairs while maintaining the scalability of hub-based control.

So the best description is that hub-and-spoke funnels traffic through central hubs, while partial-mesh enables direct site-to-site tunnels for some site pairs. The other options don’t fit because hub-and-spoke does not inherently provide universal direct site-to-site tunnels, full mesh is not defined by a central hub, and the two patterns are not identical in traffic patterns.