> ## Documentation Index
> Fetch the complete documentation index at: https://docs.assistable.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Diagnose a failed phone call

> Identify the failed direction and inspect the call result before changing carrier routing.

Start with the failed call's time, source number, destination number, and direction. Open **Call Center → History** and inspect **Status** and **End Reason**. Keep the call ID and any provider error. “Dial failed” is a symptom, not a diagnosis of one specific carrier setting.

## Outbound calls

1. Confirm the destination includes its country code and is a phone you are authorized to test.
2. Check the assistant's outbound number and calling hours. A request outside its configured window can be refused before dialing.
3. Confirm the destination is not the assistant's own number.
4. If the number is imported, compare its termination hostname and approved carrier authentication with the saved connection.
5. Place one controlled test and inspect the new call result before making another configuration change.

For an API workflow, keep the response error as well as the call log. A request refused before dialing may not have a normal completed-call record.

## Inbound calls

Call the number from another phone. Confirm the provider routes that exact number to the intended connection and that the connection uses the inbound origination URI shown in the Assistable **SIP connection result**. Confirm the number is assigned to the intended assistant.

Use the URI from your current result. Do not copy a historical shared hostname from an older guide.

## Calls that connect without usable audio

The import path uses TLS signaling, port 5061, and G.711 codecs. Media encryption is configured separately with **Carrier requires encrypted media (SRTP)**. Have the carrier administrator compare both sides; do not toggle encryption blindly to solve every error.

For an imported trunk, confirm the supported authentication profile and approved source addresses with the administrator or support. Saved credentials or a successful import result do not prove the carrier authenticated a call. Never allow the entire IPv4 address space as a troubleshooting shortcut.

## Verify the repair

Test incoming and outgoing calls separately. Confirm ringing/answer, intended assistant, caller ID, and two-way audio. Report the failed direction, timestamp, call IDs, and exact error if either test still fails; omit passwords and API keys.

See [outbound setup](/v3/guides/calling/outbound-calls) and [inbound setup](/v3/guides/calling/incoming-calls). For imported numbers, use the current connection receipt and confirm the supported carrier authentication and routing profile with your administrator or Assistable support.


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