VoIP call quality can be affected by many factors, including devices, network conditions, and configuration settings. All Sonar users can use this guide as a structured approach to identifying and resolving common issues, with steps for both end users and administrators.

Start with the Basics

Before diving into advanced settings, complete this quick 3-step check. These steps solve the majority of common call quality issues.

1. Check your hardware and physical connections.
   1. Ensure the Ethernet cable is securely plugged into your phone and the wall or router. 
   2. If you're using a headset, check its connection to your phone.    
   3. Ensure your microphone is not obstructed or dirty.
2. Reboot Devices. A simple reboot can often fix temporary glitches.
   1. Reboot your desk phone.
   2. Reboot your internet router and/or modem.
3. Test Your Internet Speed: Poor quality can be caused by a slow connection. 
   1. Close high-bandwidth apps (cloud syncs, video streaming).
   2. Run a speed test at a site like speedtest.net 

A good rule of thumb is to allocate approximately 100 kbps per active VoIP call; this estimate covers both the audio stream and the additional data required for transmission:

• Codec usage: A standard call using the G.711 codec requires about 64 kbps for the audio itself.
• Network overhead: Data packets (IP, UDP, etc.) add an additional 20–25 kbps.

Together, this totals roughly 85–90 kbps. Rounding up to 100 kbps per call ensures a safe buffer for minor fluctuations and helps maintain consistent call quality.

If these steps resolve the issue, no further troubleshooting may be required. If problems persist, continue with the sections below.

Troubleshooting: Dropped Calls

If you are experiencing active calls disconnecting unexpectedly or conversations ending without warning, you have dropped call issues.

Possible Causes

• Unstable or weak Wi-Fi connections
• Temporary router or modem instability
• Competing bandwidth usage from other applications or devices (e.g., video streaming, large file downloads, or cloud syncs)

Recommended Steps

1. Use a wired Ethernet connection whenever possible, as it provides greater stability than Wi-Fi.
2. Reboot your modem and router by powering them off for at least 60 seconds before turning them back on.
3. Pausing high-demand activities during calls, such as video streaming, large downloads, or system updates, can reduce bandwidth usage.
4. If calls continue to drop on a stable wired connection, collect recent call examples (dates, times, and numbers involved) and escalate to Support for further investigation.

Mobile Connection Tip

• Use Wi-Fi when stationary for stability.
• Switch to LTE if Wi-Fi is weak. 
• Be aware that call drops may occur while moving between towers. To improve reliability, you can quickly transfer calls from a Sonar app to your Mobile Number.

No Audio or One-Way Audio

If one party cannot hear the other, or audio is missing in one direction, you are experiencing no audio or one-way audio.

Possible Causes

• Incorrect audio device selection or mute settings
• Faulty headsets or cables
• Firewall or NAT blocking media traffic

Recommended Steps

1. Ensure the correct microphone and speakers are selected in both the operating system and the application/device.
2. Test the audio device in another application to confirm it is functioning correctly.
3. The network may be blocking audio if the issue only occurs on VoIP calls.
4. Admin Step: Verify SIP/RTP allowances and NAT configuration. See “Network and QoS (Admins).”

Poor Audio Quality (Echo, Static, Distortion)

If your audio may sound muffled, robotic, distorted, or has echo or background crackling, you are experiencing poor audio quality.

Possible Causes

• Damaged headsets or Ethernet cables
• Feedback from speakers and microphones
• Wireless interference
• Outdated firmware

Recommended Steps

1. Reduce speaker volume and ensure microphones are not too close to speakers.
2. Replace worn or faulty headsets and Ethernet cables.
3. Eliminate interference sources such as cordless phones, crowded Wi-Fi channels, or nearby microwaves.
4. Admin Step: Update firmware on phones and routers.

Additional Tips

• Use reliable, high-quality headsets.
• Avoid blocking the microphone on desk phones.
• Disable notifications on mobile devices to reduce interruptions.

Latency (Lag)

If there is a notable delay between speaking and hearing a response, you are experiencing call latency (commonly referred to as call lag).

Possible Causes

• High round-trip time due to routing
• Congested or overloaded network

Recommended Steps

1. Limit high-bandwidth applications during calls (e.g., cloud backups, large downloads, streaming).
2. Switch connection type: Move from Wi-Fi to a wired Ethernet connection, which removes wireless interference and usually lowers latency.
3. Reboot your networking equipment. Rebooting your modem and router can clear routing loops or temporary congestion.
4. Close VPNs (if not required). VPN encryption adds extra distance and processing, which can increase delay.
5. Check your location and consider wifi extenders. If possible, take calls closer to your router/access point to avoid weak signals and retransmissions.
6. Schedule calls strategically. For home users, latency can spike during neighbourhood “peak hours.” Shifting important calls outside these windows may help.
7. Admin Step: Adjust router QoS rules to prioritize voice traffic, and confirm the ISP link has enough upstream bandwidth with some margin.

Jitter (Choppy or Robotic Audio)

If words cut in and out, or voices sound robotic, you are experiencing call jitter. 

Possible Causes

• Unstable Wi-Fi or fluctuating bandwidth
• Packets arriving late or out of order

Recommended Steps

1. Use wired Ethernet instead of Wi-Fi.
2. Reboot the router to clear transient network issues.
3. Admin Step: Configure jitter buffers and QoS on phones and routers.

Offline Phone (Not Registered)

If your desk phone will not register and cannot place or receive calls, you are experiencing an offline or unregistered device.

Possible Causes

• Faulty Ethernet connections
• No IP address assigned
• SIP ALG is enabled on the router or firewall

Recommended Steps

1. Confirm that the Ethernet cable is securely connected to the LAN port. Test with an alternate cable or port.
2. Check the phone’s IP address in Settings → Status → TCP/IP Parameters. If no IP is assigned, the device is not connected to the network.
3. Admin Step: Disable SIP ALG on the router or firewall. Note that some consumer devices, such as Bell Hub 1000/2000, do not allow SIP ALG to be disabled and are not suitable for VoIP.
4. If the issue persists, gather details and contact Support.

Outbound Caller ID Problems

Outbound caller ID may display incorrectly due to carrier delays, device settings, or portal configuration.

Possible Causes

• Carrier database updates, which may take up to 60 days when a new number is acquired
• Incorrect outbound caller ID settings in the Sonar portal
• Device-level configurations can interfere with the caller ID display

Recommended Steps

1. Verify your outbound caller ID in the Sonar portal.
2. Confirm the recipient has the correct number saved in their contacts.
3. If the issue persists, collect call examples (date, time, number dialled) and provide them to Support for carrier verification.

Spam Calls

Organizations may experience unwanted or fraudulent calls. Carriers and mobile devices detect spam using caller ID checks, call frequency patterns, geographic data, and user reports.

iPhone Features

• Caller ID authentication
• Spam alerts for repeated calls
• Support for third-party call-blocking apps
• “Silence Unknown Callers” option

Android Features

• Built-in caller ID spam alerts
• Call-blocking apps
• Automatic call screening (Google Assistant on some models)

Possible Causes

• Industry-wide spam activity or insufficient filtering
• Carrier-level issues with caller ID propagation
• Incorrect outbound caller ID configuration

Recommended Steps

• Use built-in iOS and Android spam-blocking features or third-party blocking apps.
• Verify outbound caller ID configuration in the Sonar portal.
• If unwanted calls or caller ID problems persist, collect examples and escalate to Support for further investigation.

Devices and Accessories: Maximize Call Quality

The devices and accessories you use have a significant impact on call quality. 

Considerations 

• How much do I expect my business to grow?
• Is customer engagement and success a top priority?
• Do I need accurate data on call performance?
• Will my team rely on mobile devices for work?

External Devices and Accessories

Different devices and accessories provide varying levels of call quality. For example, handsets, speakerphones, and headsets can all offer different audio experiences.

1. Switch to headsets: If you’re using a handset in a noisy environment, a headset may help block out background noise and improve clarity.
2. Invest in quality headsets. Poor-quality headphones and Bluetooth devices can lead to poor call quality. We recommend investing in a reliable, high-quality headset for consistent performance.
3. Update your devices. If you’re using older mobile phones with many apps running, this could negatively impact call quality. Consider upgrading. 
4. Manage your incoming notifications. If using headphones with a mobile device, disable app notifications to prevent interruptions during calls.

Advanced Steps: Optimizing Your Network

If you are an IT administrator or a network engineer, review our advanced troubleshooting and networking recommendations. 

Core Guidelines

• Minimize packet loss and jitter; keep latency stable.
• Allocate sufficient bandwidth per concurrent call (approximately 100 kbps per call, codec dependent).

Firewall and NAT

• Allow SIP signalling and RTP media.
• Disable SIP ALG to prevent interference with call setup and media.

QoS

• Ensure your router is configured with QoS to prioritize VoIP traffic over other wireless activities.
• Learn why traffic shaping is essential with VoIP. 

Additional Resources

• Optimization Guide for Enterprise Networks
• Router-specific setup guides (Netgear, SonicWALL)
• Deployment Test Plan for New Customers
• How to get the best call quality with your home internet. 

When to Contact Support

If troubleshooting does not resolve the issue, contact Support and include the following details if possible:

1. Two to three recent example calls (with date, time, and time zone).
2. Call direction (inbound, outbound, or both).
3. Device and connection type (desk phone model, softphone, mobile; wired or Wi-Fi; VPN use).
4. Results of speed, latency, or jitter tests (or screenshots).

How to reach Support

• Dial 611 from any net2phone Canada device
• Call 1-877-498-3772 (option 3)
• Email support@net2phone.ca (include call examples)

Providing complete information helps our team identify and resolve issues quickly.