In the context of WANs, a brownout is an episode of unknown duration where congestion-based packet loss and increases in latency and jitter cause poor application performance.
While most routing and SD-WAN systems properly handle “blackouts” (total link, device or WAN connection failure), a traditional router system and many SD-WAN solutions do nothing in the face of WAN brownouts. However, a failsafe SD-WAN solution can continue to deliver high Quality of Experience (QoE) in the face of a WAN brownout through techniques such as packet replication or sub-second switching of network packets to WAN connections not experiencing brownout conditions.
Has your Network Experienced a Brownout?
While it is easy to tell if a network has experienced a power outage (or blackout) it can be more difficult to know if a network has experienced a brownout. Sometimes people complain about a “slow network,” but they may actually be experiencing an ongoing brownout due to a load reduction. By reviewing information from network management systems, the network administration will be able to better identify what is happening and if it could be associated with a brownout.