QoS — Quality of Service

Quality of Service (QoS) is a set of network management techniques that prioritize certain types of internet traffic over others. For VoIP, QoS ensures that voice packets are processed and transmitted before less time-sensitive data — like file downloads, video streaming, or email — so call quality remains consistent even when the network is busy.

Voice calls are extremely sensitive to delay and packet loss. Even a 150ms one-way delay or 1% packet loss can make a call noticeably worse. When a network is congested — multiple users downloading files, streaming video, or running cloud backups — voice packets can be delayed or dropped, causing choppy audio, echo, or dropped calls. QoS prevents this by tagging voice packets with high priority and ensuring routers and switches service them first.

QoS is typically configured on business routers and network switches. Most modern business routers include built-in QoS settings that can be configured to prioritize SIP and RTP traffic (the protocols VoIP uses). For businesses deploying VoIP for the first time, enabling QoS on the router is one of the most impactful steps for ensuring consistent call quality. Zonitel's onboarding team provides QoS configuration guidance as part of the setup process.