IP Office Used as Enterprise Branch

[sfrits]

Have site with IP Office systems used as Enterprise Branches with Avaya CM and Session Manager. If calls come in to the CM and are answered on a CM telephone when the call is placed on hold the caller hears the music. If the call comes in via the trunks on the IP Office Branch system and is then directed to an IP set at the IP Office location that is registered on the CM and placed on hold the caller hears no music. Believe the music on hold is provided and controlled by and at the CM/Session manager side but can't figure out why the telephones at those locations do not hear the music when the caller is placed on hold. Any one run in to this issue before?

[weiss1]

Not exactly the same situation, as this one has a lot of prereq's.
But I understand, your call comes in through a trunk of the IP Office, then goes its way to the CM and back to a IPO-Phone (not sure).
I think you would need a MoH source on the IPO for this.