you can redefine ringing in ld 56, but read the text very carefully. in cls for digital phone use drg1, drg2 etc to get different tones. those are defined in ld 56. so is internal and external ring cadance/freq. the only problem i have seen is some fax machines don't answer for a short then long ring so turn that one around, one long one short before you turn it on...johnP