If it's a 100D, you can "dump trk" and get a listing of all trunks and their type (DIL or normal). For DIL trunks, the DIL command will allow you to specify a day location to ring and a night location to ring. For normal trunks, the ring command allows you to assign ringing to several stations. DIL trunks are "owned" by a station, so they will hunt/cover/forward to voicemail or other coverage destinations. Normal trunks will not forward, they just ring until answered because no station owns the call.