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.