What do you mean by “ring music”?
Where are you hearing this?
Are yhou referring to rinbgback (caller) or to actual ringing (callee)?
Is the 180 going to or coming from the ATA?
Note that the party receiving the 180 is normally responsible for generating ringback, so, if Asterisk is sending to 180 to the ATA, the ATA is responsible for the ringback.
Also note that the normal text for 180 is Ringing, although only the number matters. Trying is associated with 100 and does nothing other than confirming the receipt of the invite and therefore stopping retransmissions.
What are the options on the Dial application call?
Do you call anything that would answer the incoming call (Answer, Playback, etc.) before calling Dial? Do you call Progress before calling Dial? (Ideally provide verbose level 3 CLI output.