Troubleshoot SIP trunk connection problems and configuration issuesThis guide helps resolve common SIP integration issues when connecting your SIP provider to Famulor.
Testing Strategy
- Test outbound calls first – easier to configure
- Test inbound calls second – after outbound works
Outbound SIP Issues
Connection Problems
SIP trunk not connecting for outbound calls:- Verify SIP credentials – username, password, server details
- Phone type selection – check with provider for correct type
- Fixed IP configuration – usually enable and enter provider’s IP address
- Provider settings – verify codec, transport, port settings
SIP Registration Issues
Important: Famulor platform:- Does NOT send SIP REGISTER messages to your provider
- Does NOT require receiving SIP REGISTER from your provider
- Uses direct call authentication instead
Testing Outbound
- Configure SIP trunk settings
- Make a direct test call through the platform
- Check call logs for errors
Inbound SIP Issues
Authentication Setup
For inbound calls:- Use IP authentication – instead of username/password
- Whitelist provider IPs – add ALL provider IPs in our platform
- Provider configuration – IMPORTANT
- Use our FQDN domain for routing (NOT the outbound IP)
- Send to domain – ensures correct routing
- Do NOT send to IP – causes routing issues
Common Inbound Issues
Calls not reaching assistant:- Verify all provider IPs whitelisted
- Ensure provider sends to FQDN domain (not IP)
- Check destination number format
General Issues
Network problems:- Check internet connectivity
- Verify no firewall blocking SIP traffic
- Verify provider supports direct calling (no registration)
- Check IP authentication support
Testing Checklist
Before Contacting Support
-
Outbound test:
- Credentials verified
- Phone type selected correctly
- Fixed IP enabled with provider’s IP address
- Direct test call attempted
-
Inbound test:
- IP authentication configured
- All provider IPs whitelisted in our platform
- Provider configured to send to FQDN domain (not direct IP)
- Test call from external number
-
General:
- Network connectivity verified
FAQ
Transfer Phone Call Not Working
Q: Why is the Transfer Phone Call function not working? A: If call transfers are failing, try these solutions:-
Check SIP transfer settings:
- Set transfer call to “Advanced” mode
- Use SIP URI format:
sip:number@sip-server - Example:
sip:+1234567890@sip.provider.com:5060
-
Verify provider support:
- Confirm your SIP provider supports SIP REFER
- Check if transfer functionality is enabled on your account
- Some providers require specific configuration for transfers
-
Test different formats:
- Try with port:
sip:+1234567890@sip-server:5060 - Try without port:
sip:+1234567890@sip-server - Try simple format:
sip:+1234567890
- Try with port:
-
Verify destination:
- Ensure the target number is reachable
- Test if the number answers calls normally
- Check if the number is blocked or restricted
-
Common issues:
- Provider doesn’t support SIP REFER
- Incorrect SIP URI format
- Network/firewall blocking transfer requests
- Destination number not answering
- Test with a known working number first
- Try different SIP URI formats
- Contact your SIP provider to confirm transfer support
- Check call logs for specific error messages
Getting Help
When contacting support, provide:- Error messages from call logs
- SIP trunk configuration
- Test results (outbound and inbound)
- Transfer attempt details and SIP URI format used

