SD-WAN (software-defined wide area network) is a way to use and manage several connections at the same time. For example, two fibre lines and a 4G or 5G backup connection.
The software continuously checks which connection performs best and sends the traffic there. Video calls, for example, go via the connection with the lowest latency. If a connection fails, it switches over automatically.
SD-WAN is mainly used by organisations with several locations, or in buildings where redundancy matters.
What does this mean for the IT-Label?
SD-WAN helps with Connectivity: it combines several connections and switches over automatically if one fails. That contributes to redundancy and stability. It is not an IT-Label requirement, but in buildings with multiple connections it makes redundancy more usable. See also latency.