Most calling problems are related to network restrictions, especially firewall or Wi-Fi settings. Please follow the steps below.
No Sound or Call Not Connecting
If you cannot hear the caller, the caller cannot hear you, or the call cannot connect, it is usually caused by the network. Please try the steps below:
Check your network and firewall: Calling requires a stable and open network connection.
Make sure your network or firewall allows voice calls. You can review Twilio’s official requirements here: https://www.twilio.com/docs/voice/sdks/network-connectivity-requirements#firewall-configuration
Run a quick network test on the device having the issue. This test will tell you if your network is blocking audio traffic. https://networktest.twilio.com/
Check your network environment: Some networks may block voice calls. If you are using one of these, the network may be the cause, including:
Company VPN
Office Wi-Fi
Public Wi-Fi with restrictions
Try another network: Switch to a different network (for example, a mobile hotspot) and make a test call again.
If the call works on the new network, then the issue is caused by the original network’s firewall or restrictions.
If you have tried all the steps above and the issue continues, feel free to contact us. We’ll gladly help check for system-side issues.