[Home](./index.md) > [sip.js](./sip.js.md) > [SessionDescriptionHandler](./sip.js.sessiondescriptionhandler.md) > [holdModifier](./sip.js.sessiondescriptionhandler.holdmodifier.md) ## SessionDescriptionHandler.holdModifier() method The modifier that should be used when the session would like to place the call on hold. Signature: ```typescript holdModifier(sessionDescription: RTCSessionDescriptionInit): Promise; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | sessionDescription | RTCSessionDescriptionInit | The description that will be modified. | Returns: `Promise` Promise that resolves with modified SDP. Rejects with `ClosedSessionDescriptionHandlerError` when this method is called after close or when close occurs before complete.