think I figured out the binary bit thing, so I am posting to list to hopefully help someone else out bits 15-8 are all 0 and are reserved bit 7: value 0: numeric 8 reserved bit 6: value 0: numeric 4 reserved bit 5: value 0: numeric 2 dtmfmethod bit 4: value 1: numeric 1 dtmfmethod bit 3: value 0: numeric 8 [CNG fax tone] bit 2: value 0: numeric 4 [CED fax tone] bit 1: value 1: numeric 2 [g711 codec only: 1 true 0 false] bit 0: value 0: numeric 1 [silence suppression 1 on 0 off] so that makes 0012 for each line, or 0x00120012