External Transfer Call
The External Transfer Call scenario block transfers calls to an external number specified in the block’s Destination field.
Notes:
- This block works only if your VoIP telephony carrier allows the feature for your contact center.
- This block is shown in the Scenario Builder application only if the Allow using network transfers (SIP REFER) on trunk-to-trunk calls to avoid trombones feature is enabled in the Service Provider application.
- Use this block when you want to transfer an active call to an external destination and remove the contact center from the call path. This can reduce bandwidth usage and call latency, since the call no longer passes through Bright Pattern infrastructure.
- Use the Connect Call block when Bright Pattern must remain involved in the call, such as for call recording, call monitoring, or guaranteed visibility into call completion.
- This block only works if you have an existing call to or from a customer; it cannot work if there is no call leg on a trunk already.
- Note that the scenario terminates immediately after the transfer and there is no call recording beyond the transfer. For more information about using this block in a scenario, see Redirect Calls Economically with a Single-Step External Transfer Option.
- If the transfer cannot be initiated (e.g., the call is not on a trunk or the carrier does not accept transfer requests), the block will take the Transfer Failed conditional exit. In this case, it is still possible to continue with the call and use Connect Call block to bridge it to a destination.
When this block is executed, Bright Pattern sends a SIP REFER request to the external trunk associated with the current call, requesting that the trunk connect the call to the specified external destination.
If the external trunk accepts the transfer request, it disconnects Bright Pattern from the call and independently attempts to connect the call to the destination number. Once Bright Pattern is removed from the call, it no longer participates in the media path.
This block is typically used when you want to remove the contact center from the call path in order to reduce bandwidth usage and call latency. While cost reduction may occur in some scenarios, it is generally not the primary motivation for using this block.
The external trunk is not required to honor transfer requests. For example, if the transfer would result in a long-distance or otherwise costly call, the trunk provider may reject the request because it would be responsible for the call charges.
If the external trunk accepts the SIP REFER request, Bright Pattern treats the transfer as successful and disconnects from the call. Any subsequent failure—such as an invalid destination number, no answer, or rejection by the destination—is handled entirely by the external trunk and is not reported back to Bright Pattern, therefore any functionality issues past this step must be addressed with the destination carrier.
Call recording stops once Bright Pattern is disconnected from the call.
The following sequence summarizes how the External Transfer Call block operates:
1. An active call is connected through an external trunk
2. The scenario reaches the External Transfer Call block
3. Bright Pattern sends a SIP REFER request to the external trunk
├─ If the REFER request is rejected: │ - Bright Pattern remains connected to the call │ - The Transfer Failed conditional exit is taken
└─ If the REFER request is accepted:
- The external trunk disconnects Bright Pattern from the call
- Bright Pattern has no further visibility or control
- The external trunk attempts to connect the call to the destination
- Any success or failure at this stage is not reported back
Conditional Exit
Transfer Failed
The Transfer Failed conditional exit is taken if the call transfer failed. Transfers may fail because:
- The Destination field is empty
- The feature is not allowed for your contact center
- Your service provider has not configured the appropriate trunk setting
- The call does not originate from the trunk (e.g., from a softphone or a hardphone extension)
- The transfer request (SIP REFER) receives any response code other than the successful code (i.e., 202 Accepted)
The transfer is considered failed if the external trunk rejects the SIP REFER request. In this case, Bright Pattern remains connected to the call, and the scenario continues along the Transfer Failed path.
If the external trunk accepts the transfer request, Bright Pattern is disconnected from the call and no further scenario processing related to the call is possible.
Settings
Title Text
Title text is the name of the instance of the block. Enter a name in the text field and click the Save button at the bottom of the Edit pane. The new name of the block appears in the flowchart.
Destination
Destination is the phone number the call will be transferred to. You may enter either a phone number or a variable in this field.
Bright Pattern does not initiate a new outbound call to the destination. Instead, it requests that the external trunk take over the call and attempt to connect it to the specified number.
