Quality of Service is a set of network rules that give voice data priority over other traffic. On a busy connection, QoS ensures call packets move first, preventing the choppy audio and dropouts that come from congestion.
For VoIP, QoS is the difference between reliable calls and frustrating ones. It works alongside a jitter buffer to keep latency and packet loss low.
A well-run cloud phone service handles QoS for you, so calls stay clear without your team tuning the network.