# Poor VoIP call quality: diagnose jitter, packet loss and delay Published by Britixo | 2026-10-29 | Communications Canonical page: https://britixo.com/business-guides/voip-call-quality-jitter-packet-loss/ Diagnose poor voice quality by comparing affected calls, devices and network paths before changing settings. Jitter is variation in packet arrival time, packet loss means audio data did not arrive, and latency contributes to conversational delay. A speed test alone cannot separate these problems. Gather call timestamps and media statistics, reproduce the issue under controlled conditions, and change one part of the path at a time. ## When this guide is useful IT managers, office administrators and support teams investigating unreliable business calls - Speech sounds robotic or syllables disappear during otherwise connected calls. - Users talk over one another because conversation is delayed. - Calls are acceptable on a wired connection but poor on office Wi-Fi. - Quality deteriorates during uploads, backups or busy periods. ## Describe the failure precisely Record a small set of affected and unaffected calls. Include time with time zone, extension or user, device, connection type, site, direction of the call and the symptom each participant heard. Use permitted call identifiers rather than collecting unnecessary recordings or customer information. The comparison matters more than a long list of vague complaints. Check whether the problem affects one headset, one office, all external calls or only calls to a particular destination. One-way audio, dropped calls and distorted speech can have different causes. Ask whether the issue started after a network, VPN, firewall, software or device change; retain the change reference alongside the call evidence. ## Use media telemetry and a controlled comparison Microsoft's call-health documentation shows how Teams exposes packet loss, jitter and round-trip time. Other platforms offer equivalent information through their administrative tools. Interpret measurements using the platform's current guidance and the timing of the symptom, rather than applying one threshold as a guarantee of acceptable speech. Compare the same supported device on a wired connection and on the affected Wi-Fi, where authorised and practical. Test with a known-good headset and current supported client. Keep the destination and workload comparable. If one change removes the fault, repeat the test before concluding that every problem has the same cause. ## Repair the constrained part of the path For a shared network, examine congestion in both directions, Wi-Fi coverage, access-point load and the route used by real-time media. A fast download result does not rule out an overloaded uplink or intermittent wireless interference. Separate evidence about the local network from evidence about the internet or voice service. Microsoft recommends considering network readiness and quality-of-service configuration for Teams. In a managed environment, prioritisation must be designed consistently along the controlled path. Do not disable security controls or apply generic router fixes blindly. Make scoped changes with the network owner and confirm that required voice traffic remains securely supported. ## Verify under normal business load Repeat the affected call scenarios during the time and load conditions in which they originally failed. Compare the media measurements, perceived quality and failure frequency. Include both inbound and outbound calls, remote users and any devices that were part of the issue. A quiet weekend test may miss the weekday bottleneck. If the evidence points beyond your network, provide the service provider with precise call references and a concise timeline. Ask for findings against those calls instead of a general assurance that the platform is healthy. Establish a lightweight monitoring baseline and an escalation route so recurring degradation is recognised sooner. ## Prepare for a useful conversation - Affected and successful call examples with timestamps and time zones. - Device, client, headset and connection details for each comparison. - Relevant jitter, packet-loss and delay observations without unnecessary personal data. - A network diagram showing Wi-Fi, VPN, internet egress and voice dependencies. - A change log and repeatable acceptance test during representative load. ## How Britixo can help Britixo can investigate business voice problems across the supported calling configuration, endpoints and network dependencies within an agreed scope. The work can include an evidence-led assessment, call-flow and device checks, coordination with your connectivity or voice provider, and a prioritised remediation plan. Where network changes or monitoring are needed, responsibilities and acceptance criteria are agreed before implementation. Bring a few recent failed call examples and one successful comparison to the initial discussion; this helps focus the investigation on the service your team actually experiences. [Contact Britixo](https://britixo.com/contact/?enquiry_type=contact_consultation#contact-form) ## Common questions ### Will buying more bandwidth fix robotic audio? It may help if congestion is the cause, particularly on the uplink, but it will not automatically fix wireless interference, device faults or an unsuitable media route. Compare call telemetry and network utilisation before changing the circuit. ### Is Wi-Fi always unsuitable for business calling? No. A properly designed wireless network can support voice, but coverage, congestion and movement between access points affect the experience. A wired comparison is a useful diagnostic step, not proof that every user must permanently use a cable. ### Should we record every poor call? Usually timestamps, call references and technical metrics are a better starting point. Recordings may expose personal or confidential information and need appropriate permissions and retention controls. Use the least intrusive evidence that allows the issue to be investigated. ## Related guides - [UK PSTN switch-off: a practical business migration checklist](https://britixo.com/business-guides/uk-pstn-switch-off-business-checklist/) - [Reduce missed business calls with better routing and follow-up](https://britixo.com/business-guides/reduce-missed-business-calls/) - [Microsoft Teams Phone or a cloud PBX: how to choose](https://britixo.com/business-guides/microsoft-teams-phone-vs-cloud-pbx/) ## Sources and further reading - [Microsoft: monitor call and meeting quality](https://support.microsoft.com/en-us/teams/meetings/monitor-call-and-meeting-quality-in-microsoft-teams) - [Microsoft: prepare your organisation's network for Teams](https://learn.microsoft.com/en-us/microsoftteams/prepare-network) Prepared with AI assistance and checked against linked primary documentation. [Editorial approach](https://britixo.com/business-guides/#editorial-approach). 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