What Is Network Latency and Why It Matters for VoIP Phone Quality
VoIP phone calls are remarkably demanding on your network infrastructure — not in terms of bandwidth, but in terms of consistency and timing. A video file that downloads 50 milliseconds late is undetectable. A voice packet that arrives 50 milliseconds late is heard as choppy, robotic audio that makes your calls sound unprofessional and difficult to understand. Understanding the network metrics that affect VoIP call quality is the foundation of troubleshooting and preventing call quality problems.
The Three Network Metrics That Affect VoIP Quality
Latency is the time it takes for a voice packet to travel from the sender to the receiver. Acceptable VoIP latency is under 150 milliseconds one-way (under 300 milliseconds round-trip). Latency above 150 milliseconds creates noticeable delays that cause callers to talk over each other, producing the frustrating pause-and-overlap pattern of a poor call. Jitter is the variation in latency — packets arriving at irregular intervals rather than at consistent timing. Even if average latency is acceptable, high jitter causes audio packets to arrive out of order or bunched together, creating the “robotic” audio quality associated with poor VoIP calls. Acceptable jitter is under 30 milliseconds. Packet loss occurs when voice packets fail to reach their destination entirely. VoIP protocols can compensate for occasional packet loss using concealment algorithms, but packet loss above 1 percent produces audible audio gaps and call degradation.
Common Causes of Poor VoIP Network Quality
Network congestion from other applications consuming bandwidth simultaneously is the most common cause — file downloads, video streaming, or software updates competing with VoIP traffic for bandwidth. Lack of Quality of Service (QoS) configuration allows non-time-sensitive traffic to compete equally with VoIP packets. Consumer-grade routers and switches that cannot prioritize traffic types effectively degrade under load. Wi-Fi interference from neighboring networks, physical obstacles, or device density causes packet loss and jitter that wired connections avoid entirely. Overloaded internet circuits with consistently high utilization leave no headroom for the burst traffic that VoIP calls require.
How to Fix VoIP Quality Problems
Implement Quality of Service (QoS) on your router to prioritize VoIP traffic over all other traffic types — this single step resolves the majority of VoIP quality issues on adequate internet connections. Move VoIP phones to a wired connection if possible, or ensure strong Wi-Fi signal for wireless devices. Assess your internet utilization — if your connection is consistently near capacity, upgrading speed or adding a second connection with VoIP-specific routing is necessary. Test your network with a VoIP-specific network assessment tool that measures latency, jitter, and packet loss under load.
Vivant’s Network Quality Management
Vivant’s managed network service includes QoS configuration optimized for VoIP performance, network monitoring that alerts our team to quality degradation before you notice it on calls, and proactive remediation of the network issues that cause VoIP quality problems. When you deploy Vivant’s phone system alongside Vivant’s managed network service, call quality is our responsibility end-to-end. Contact Vivant for a free network assessment if you are experiencing VoIP quality issues.
