Dropped Calls & One-Way Audio

Reliable phone service is essential for effective communication. When calls drop unexpectedly or audio becomes one-way, it can disrupt your workflow and impact productivity.

This guide provides systematic approaches to identify and resolve the most common call issues. We'll progress from basic checks to more advanced troubleshooting steps, helping you restore normal service efficiently.

➡️In this guide:

• Initial quick fixes to try immediately

• How to distinguish connection problems from voice quality issues

• Step-by-step solutions for dropped calls and one-way audio

• Information to gather before contacting support

✅Quick Checklist

Start with these basic checks before proceeding to detailed troubleshooting:

• Restart your IP phone and network equipment (router/modem)

• Verify other internet services are functioning normally

• Ensure no large downloads or uploads are running during calls

• Confirm your phone displays a "Registered" or "Ready" status

🛠️Start Here: Identify Your Problem

First, determine which type of issue you're experiencing:

⚙️Section 1: Understanding the Difference – Quality vs. Stability

Important note: Good voice quality does not guarantee call stability.

Consider these distinct aspects:

• Voice quality refers to audio clarity during an active call

• Call stability refers to whether the connection remains established

A call may have excellent audio quality but still disconnect due to signaling or connectivity problems. This guide focuses primarily on resolving connection stability issues.

⚙️Section 2: Fixing Connection Problems (Dropped Calls & One-Way Audio)

Firewall and NAT Issues

Firewalls provide essential network security but can sometimes interfere with VoIP traffic.

Recommended solutions:

1. Disable SIP ALG (Application Layer Gateway)

   • SIP ALG is a router feature that frequently disrupts VoIP traffic

   • Access your router settings and locate "SIP ALG" or "SIP Passthrough"

   • Disable this feature and test your service

   • Note: This resolution addresses many one-way audio cases

2. Configure firewall ports

   • SIP signaling: typically UDP 5060 or UDP 5061

   • RTP (audio traffic): port range UDP 10000-20000 (confirm with your provider)

   • Ensure bidirectional traffic is permitted on these ports

3. Review port forwarding settings

   • Devices requiring external access may need port forwarding configured

   • Standard internal setups typically only require outgoing and return traffic

Network and Bandwidth Considerations

Indicators: Calls drop during peak usage times or when large data transfers occur.

Solutions:

1. Monitor bandwidth consumption

   • Check for bandwidth-intensive activities (streaming, gaming, large downloads) occurring during calls

   • Use your router's administration interface to observe real-time usage

2. Implement Quality of Service (QoS)

   • Configure QoS on your router to prioritize VoIP traffic

   • Assign highest priority to SIP signaling and RTP audio streams

   • This ensures call quality during network congestion

3. Perform speed tests

   • Conduct tests at speedtest.net during problematic periods

   • Minimum requirements per call:

     • Download: 1 Mbps

     • Upload: 1 Mbps

     • Ping: Under 100ms

     • Jitter: Under 30ms

Device and Registration Issues

Indicators: Phone fails to ring, cannot initiate calls, or service intermittently unavailable.

Solutions:

1. Verify registration status

   • Check your phone's display or status menu

   • Confirm "Registered," "Ready," or equivalent status appears

   • "Not Registered" or "Failed" indicates connectivity issues with our servers

2. Review device configuration

   • Verify SIP server address, username, and password accuracy

   • Verify extension numbers and domain settings if applicable

   • Perform proper device restart sequence

     • Step 1: Power off modem → Wait 30 seconds → Restore power → Wait 2 minutes

     • Step 2: Power off router → Wait 30 seconds → Restore power → Wait 2 minutes

     • Step 3: Restart IP phone

3. Update device firmware

   • Contact your respective support technician to verify the current firmware version and determine if an update is recommended

   • The support technician can assist with locating the appropriate firmware from the manufacturer's support website

   • They will also ensure proper update procedures are followed to maintain device configuration and service continuity

   • Keeping firmware current under technician guidance ensures optimal compatibility and performance

4. Isolate device-specific issues

   • Test an alternative phone on the same connection

   • Test the suspect phone on a different network

   • This helps determine whether the issue is device-specific

⚙️Section 3: Addressing Voice Quality Problems

Use this section when callers report robotic, choppy, or delayed audio.

Diagnostic Tests

1. Packet loss assessment

   • Open command prompt (Windows) or terminal (Mac)

   • Enter: ping -t 8.8.8.8 (Windows) or ping 8.8.8.8 (Mac)

   • Allow test to run during a problematic call

   • Press Ctrl+C to stop and review for "Request timed out" or packet loss percentage

2. Wi-Fi signal evaluation

   • Check signal strength on cordless or Wi-Fi phones

   • Temporarily move closer to the access point for testing

   • Consider wired connections for fixed installations

3. Jitter and latency testing

   • Use online VoIP testing tools (e.g., testmyvoip.com)

   • Target parameters:

     • Jitter under 20ms (optimal)

     • Latency under 150ms

🟢Resolution Guide for Voice Quality Issues

⚙️Section 4: Escalation – Information for Support

If issues persist after completing all applicable steps, please contact your support represntative with the following information to expedite resolution:

Required Information

1. Issue timeline

   • Specific times when problems occur

   • Frequency pattern (every call, intermittent, related to specific activities)

2. Troubleshooting completed

   • Steps from this guide already attempted

   • Any configuration changes made

3. Equipment details

   • Phone make, model, and firmware version

   • Router make and model

   • Internet service provider

4. Test results

   • Speed test results during problematic periods

   • Ping test outputs showing packet loss if applicable

   • MOS scores from call history if available

5. Call specifics

   • Affected phone numbers

   • Date and time of problematic calls

   • Whether issue affects inbound, outbound, or both call types