Distinctive ringing is not working on route 22 and 30 but it works in route 17. It looks like the configuration are same..Looking at customer's configuration, NDRG is set to yes and ATDNs are defined for incoming trunks. And these ATDNs are MCR keys for the sets we have. So when a call comes from a trunk, it auto terminates to the ATDN and since this is the MCR key, the phone should ring distinctively. But it only works fine for the trunks in route 17...