     7   6   5   4   3   2   1   0   7   6   5   4   3   2   1   0
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
00 | Type                      | Analog contact index, 0xff=none   |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

Some field details:
 - Type: 0=none, 1=DTMF, 2=2Tone, 3=5Tone
