[Home](./index.md) > [sip.js](./sip.js.md) > [SessionDescriptionHandler](./sip.js.sessiondescriptionhandler.md) > [sendDtmf](./sip.js.sessiondescriptionhandler.senddtmf.md) ## SessionDescriptionHandler.sendDtmf() method Send DTMF via RTP (RFC 4733). Returns true if DTMF send is successful, false otherwise. Signature: ```typescript sendDtmf(tones: string, options?: any): boolean; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | tones | string | A string containing DTMF digits. | | options | any | Options object to be used by sendDtmf. | Returns: `boolean` True if DTMF send is successful, false otherwise.