Call to a group, but sending audio message to all the group

Hello all,

i am quite new asterisk, and looking for some help for a particular issue:

I would like to send an audio message like “good morning all” to a group of phones, configuring the phones fore auto answer. Is it possible trough asterisk ? Should it be done with a multicast ip on all the phones of the gorup ?

many thanks,

greetings,
angelo