[Home](./index.md) > [sip.js](./sip.js.md) > [OutgoingRequestDelegate](./sip.js.outgoingrequestdelegate.md) > [onTrying](./sip.js.outgoingrequestdelegate.ontrying.md) ## OutgoingRequestDelegate.onTrying() method Received a 100 provisional response. Signature: ```typescript onTrying?(response: IncomingResponse): void; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | response | IncomingResponse | Incoming response. | Returns: `void`