When an outbound call is made and the call has a status of not_connected, it means that the outbound call has not successfully established the connection to the destination number. There are a few reasons for this, and it is tracked in the disconnection_reason field of the call.

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Disconnection reasons for not connected calls

  • invalid_destination: representing cases where the destination phone number is invalid.
  • telephony_provider_permission_denied: representing cases where the sip trunk authentication failed.
  • telephony_provider_unavailable: representing cases where the telephony provider is not available or has errors.
  • sip_routing_error: representing cases where there are loops or issues with the sip routing.
  • marked_as_spam: representing cases where the call is marked as spam. Read more about root cause and remediation methods below.
  • user_declined: representing cases where the user explicitly declined the call.
  • dial_failed: representing cases where sip error codes are not available, or error is unknown.
  • dial_busy: The number dialed is busy.
  • dial_no_answer: The number dialed did not answer.

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Steps to troubleshoot

1

Check the call history and detailed log. It contains the disconnection reason, the SIP error code, and the error message. In most cases, this would be enough for you to identify the root cause.
2

If the call detailed log does not provide enough information, you can try the following:
  • If using custom telephony
    1. Double check your configuration and make sure you imported the right information. Refer to FAQ for more info.
    2. If the configuration is not correct, delete the imported number and re-import.
    3. If that does not solve it, please check with your telephony provider to see what’s the error on their side.
  • If using numbers purchased from Retell
    1. Make sure the destination number can accept the call. Currently, numbers purchased from Retell can only make calls to US numbers.

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Number marked as spam

When a number experiences high outbound call volume spike without any warmup, and/or has a low pickup rate, it might be marked as spam by carriers. When this happens, the number will get blocked frequently. To remedy this, you can try to:
  • Purchase a new number, and warm it up before pouring all traffic to it (slowly add outbound traffic to it)
  • Increase the pickup rate, read more at Increase Pickup Rate
  • Register the number with our spam remediation feature, read more at verified phone number