Software-Defined WAN (SD-WAN): Underlay vs. Overlay Networks, IPsec Tunnels and SASE Integration
For decades, enterprise Wide Area Networking (WAN) relied on rigid, expensive, and carrier-locked private transport circuits—predominantly Multiprotocol Label Switching (MPLS) and leased T1/E1 lines. While MPLS provided guaranteed bandwidth and deterministic Quality of Service (QoS), its exorbitant cost per megabit, months-long provisioning lead times, and centralized ‘hub-and-spoke’ backhauling architecture became major bottlenecks as corporate applications … Read more