VoIP call-quality checklist

Before launch

Test internal, external, Wi-Fi, VPN, queue, transfer, DTMF, recording, and fax paths.

Confirm codec agreement and RTP reachability.

Measure loss, jitter, delay, and peak-period congestion.

Verify QoS markings and queue treatment.

Record a baseline and acceptance threshold.

During an incident

Capture the time, endpoints, direction, and symptom.

Check whether the problem affects signalling, media, or both.

Compare a working and failing call.

Inspect SDP and actual RTP flow.

Check Wi-Fi, WAN, firewall, SBC, and carrier events.

See the voice quality hub for detailed guides.