Parallel message to Hunt Group

Hi all, I am trying to accomplish what i am going to explain whit Hunt Group and/or Queue but nothing is perfectly what I need.

Request:
Call comes in and ring on a HUNT GROUP with LINEAR mode. After 15 seconds i want to play a greeting message that inform caller that, for istance, all line are busy and stay on the line ( or something like that… ). While message is playing, phone HAVE TO KEEP ringing…

HUNT GROUPS:
using hunt groups i can’t do it. Just use an announcment but it plays before start ringing phone…

QUEUE:
after X seconds i can play a message ( Announce Position ) but when it plays, extensions on a queue stop ringing…

Does anyone has an idea? Is possible to have this feature?
Btw, this one is a normal feature in some PBXs
Regards

I don’t believe it’s strictly possible due to the call handling. Asterisk needs to take the call back to play the announcement. You could probably hack it by recording ring tones for “hold music”, and after 15 seconds, clip in your announcement. Set up a custom music on hold group for that “music” and then set it as the music on hold for that ring group.