For 20 years, companies connected their branch offices using expensive leased lines (MPLS). It was secure but slow and costly. SD-WAN changes the game by using cheap broadband internet securely.
1. How it Works
SD-WAN creates an "Overlay Network". It builds encrypted VPN tunnels over any connection available (LTE, 5G, Broadband, Fiber).
The "intelligence" is in the software. The SD-WAN controller monitors all links in real-time. If the broadband line is jittery for Voice traffic, it instantly switches the call to the LTE line without dropping it.
2. SASE (Secure Access Service Edge)
SD-WAN connects the branch to the HQ. SASE connects the USER to the CLOUD. It combines SD-WAN with cloud-delivered security (Firewall-as-a-Service, CASB, ZTNA).