VoIP call quality on Telavox services can be impacted by several technical and environmental factors, including your internet connection, router setup, local network performance, and how devices like Wi-Fi or DECT (cordless) phones are configured. Symptoms such as audio dropouts, delay, jitter, static or echo can all affect the user experience.
This guide outlines proactive steps you can take to troubleshoot call quality before opening a support ticket.
VoIP network requirements
For best performance, ensure your network meets the following parameters:
Jitter: Less than 20 ms
Packet Packet Loss: 0%
SIP-ALG: Must be disabled in the router
Bandwidth: At least 100 kbps per call in both directions (upload and download)
Factors that can affect VoIP quality
- High-traffic activities: Large file transfers, cloud backups, IP cameras, streaming services, etc.
- VPN usage: Reroutes traffic through remote servers, extending data paths and increasing latency. Overloaded VPN servers risk congestion, causing packet loss or jitter
- Wireless instability: Wi-Fi interference (e.g., microwaves, Bluetooth devices) or poor signal strength
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Hardware & environmental factors:
- Hardware overheating: Routers, switches, or VoIP phones overheating due to poor ventilation
- Headset problems: Incompatible or outdated headsets may cause echo, distortion, or audio drops. Wireless headsets used too far from their base station may experience instability or signal loss
- Industrial equipment interference: Electromagnetic noise from machinery (e.g., HVAC systems, generators)
- Device limitations: Outdated hardware or low-quality Ethernet cables
- Configuration issues: Missing QoS settings, outdated router firmware, or SIP-ALG enabled
Self-troubleshooting steps before contacting support
- Check Telavox status page: Visit our status page to confirm whether there are any known service disruptions impacting voice quality.
- Run a VoIP test: Use a VoIP test tool during normal business hours to simulate typical traffic conditions. Repeat the test at different times of the day for comparison purposes.
- Restart your network devices: Reboot your modem, router, and any switches to eliminate temporary issues.
- Contact your internet service provider (ISP): Ask your internet service provider to check the quality of your connection—especially if your VoIP test results indicate issues like high latency, jitter, or packet loss.
Wireless environments: Wi-Fi & DECT considerations
While using cordless phones is convenient, it is more prone to interference and instability compared to wired connections.
- Wi-Fi (Softphones/Laptops): Use Ethernet whenever possible. Wi-Fi is less stable, especially in areas with many devices, thick walls, or interference. Prefer 5GHz, place access points centrally, and limit background traffic
- DECT Phones: Keep handsets close to the base with clear line of sight. Avoid placing the base near routers or metal surfaces. Low battery or interference can cause dropped or poor-quality calls
- Avoid wireless in unsuitable environments: Such as warehouses, multi-floor offices, or areas with heavy interference. In these cases, wired phones or a wireless site survey are recommended
Troubleshooting issues affecting a single user/extension
- Verify user-specific factors: Confirm no VPN usage, Wi-Fi congestion, or background apps hogging bandwidth. Inspect Ethernet cables, switch ports, and proximity to interference sources
- Compare with other users: If the user shares a network with others (e.g., office branch), test another device in the same location. If multiple users have the same deskphone/DECT model, check for possible updates. Swap the handset, horn, or horn cable with a working phone to check for hardware or connection-related problems
- Test with and without headset: If the user is using a headset, try removing it temporarily. Ensure the headset is VoIP-certified, updated with the latest firmware, and correctly connected. For wireless headsets, confirm that the user stays within range of the base station and avoids interference from nearby devices
Information to include when opening a support ticket for call quality
To help us resolve your issue more quickly, please provide:
- VoIP test results: Include results from your VoIP test, along with the name or identifier used
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Bad call samples: Provide detailed examples of the issue, including the following information for each affected call:
- A-number (Caller): The number that initiated the call
- B-number (Callee): The number that received the call
- Timestamp: Date and exact time of the call
- Issue description: Brief note on what was wrong (e.g., choppy audio, delay, echo)
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Direction of the issue:
- User cannot hear other party
- Other party cannot hear user
- Both sides affected
- Troubleshooting steps taken: Detail what you have already tried on your side (e.g., rebooted router, tested with Ethernet instead of Wi-Fi, adjusted QoS, etc.)
Definitions
Jitter: Inconsistent timing between packet arrivals. High jitter makes voices sound robotic or jumbled
Packet loss: Voice data packets that are dropped and never arrive. Causes audio gaps or choppy sound
Latency (Ping): The time it takes for data to travel from sender to receiver. Voice can feel delayed and unnatural above 150 ms, making conversations feel out of sync
QoS (Quality of Service): A network feature that prioritizes VoIP traffic over less time-sensitive data (e.g. file downloads) to ensure consistent call quality during periods of high bandwidth usage
SIP-ALG (Session Initiation Protocol – Application Layer Gateway): A router feature that tries to manage SIP traffic but often interferes with VoIP calls. It should be disabled to avoid issues like one-way audio or call drops
By following these steps and supplying the necessary information, you will either resolve the issue directly or enable our support team to assist you more effectively. Wi-Fi users should take extra care in evaluating their environment and consider switching to wired if persistent issues arise.