Outbound calls disconnect immediately – please enable outbound and inbound calling

Support Help
2

I can’t directly enable telephony permissions for your workspace—that requires support team access. However, I can help troubleshoot common outbound call issues.

If you’re using Twilio with imported numbers via SIP trunking, verify your authentication setup:(1)

Common Issues:

  1. Missing SIP Trunk Credentials - When importing a Twilio number, you need to provide either IP whitelisting or username/password authentication(2)(1)

  2. IP Whitelisting - If using IP authentication, whitelist these ranges in your Twilio SIP trunk:(3)(1)

    • 18.98.16.120/30 (All regions)
    • 143.223.88.0/21 (certain US traffic)
    • 161.115.160.0/19 (certain US traffic)

  3. Termination URI - Ensure you’ve configured the correct termination SIP URI in your Twilio trunk and provided it when importing the number to Retell(2)(1)

  4. Authentication Error - A “telephony permission denied” error typically means missing username/password credentials when importing the number(4)

To fix authentication issues:

When importing your Twilio number, include the SIP trunk credentials:(2)

const phoneNumberResponse = await client.phoneNumber.import({
  phone_number: '+14157774444',
  termination_uri: 'someuri.pstn.twilio.com',
  sip_trunk_auth_username: 'username',
  sip_trunk_auth_password: '123456'
});

(2)

For workspace-level permissions or billing issues, contact support: