QoS (Quality of Service)

QoS (Quality of Service) classifies and handles network traffic according to policy to protect applications sensitive to delay, loss or jitter, such as voice and video. It may mark, prioritise, rate-limit or queue traffic depending on equipment and path. QoS does not create bandwidth or permanently fix a saturated circuit; it decides which traffic is affected first during contention. Policy needs clear classes, trusted markings, sufficient capacity and consistent application across relevant points. Excess priority for one class can harm others. Teams should measure real patterns and establish a baseline before activation. Tests under load and per-class measures confirm whether latency, loss and queues improve without unintended effects. A configured rule does not prove end-to-end treatment if another device rewrites or ignores it.