SIP Troubleshooting - Cannot Receive Incoming Call
If you cannot receive incoming calls, check the following:
1. Double confirm your device register to SIP trunk successfully
- Successful register message show on your device or
- Login to your account, check Connected Devices to double confirm that the correct device is connected.
2. Check to confirm that you are using one of the supported codecs: G.711, G.729, GSM
3. Check your Firewall Settings
Almost all cases of which lines are unable to receive incoming calls are due to network latency fluctuations. UDP transport cannot handle very well in this case. If your SIP devices are still using UDP transport. Please switch to TCP transport.
If you have completed the above and it still does not work, please collect MTR Report and Network Capture (or SIP log) of a failed incoming call. Send both of them to our support team for further assistance.