sendTones() method of the Telephony Interface generates multiple DTMF tones, with a specified duration for each tone, and an optional delay before generation starts. The tones are sent to the currently active call.startTone() method of the Telephony Interface begins generating the tone for the specified DTMF character. The tone is sent to the currently active call, and continues to sound until a corresponding call to Telephony.stopTone().state read-only property of the TelephonyCallGroup interface returns a DOMString indicating the state of the call group.TimeRanges.length read-only property returns the number of ranges in the object.byteStreamTrackID read-only property of the TrackDefault interface returns the ID of the specific track that the SourceBuffer should apply to.kinds read-only property of the TrackDefault interface returns default kinds for an associated SourceBuffer to use when an initialization segment does not contain label information for a new track.label read-only property of the TrackDefault interface returns the default label for an associated SourceBuffer to use when an initialization segment does not contain label information for a new track.language read-only property of the TrackDefault interface returns a default language for an associated SourceBuffer to use when an initialization segment does not contain language information for a new track.TrackDefault() constructor of the TrackDefault interface constructs and returns a new TrackDefault object.type read-only property of the TrackDefault interface returns the type of track that this SourceBuffer's media segment data relates to (i.e. audio, video, or text track.)length read-only property of the TrackDefaultList interface returns the number of TrackDefault objects in the list.TrackDefault() getter method of the TrackDefaultList interface allows the TrackDefault objects in the list to be accessed with an array operator (i.e. [].)