Customer has Yealink T42S phones. When ringing back from Shared Parking, the phone plays the standard ring tone. They want it to use a distinctive ring tone. From a SIP trace, the INVITE for the ringback does not have an Alert-Info field, so they can't use the phone's distinctive ring feature. However the phone is supposed to support distinctive ring for numbers in the local directory. If I'm reading it right, the ring-back comes from "extension" SP1, but when I add that to the phone's local directory, I still can't control the ring tone. Any suggestions?