December updates are now available for Microsoft Phone Edition that enable a fixed music on hold file to play when the calling party is on hold. The file is not customizable and is embedded into the update and works with both Lync Phones devices registered to Lync 2010 and 2013.
The updates can be found here:
To install the updates: http://technet.microsoft.com/en-us/library/gg398861.aspx
1. Download and extract the .cab files from the executable
2. Type: Import-CsDeviceUpdate -Identity "service:WebServer:lswebint-na.nwiss.com"
<Note:"service:WebServer:<Your Lync FE internal Web services FQDN>
3. Ensure the client policy associated with the common area room device or user is enabled for Music
on hold: http://technet.microsoft.com/en-us/library/gg398300
Set-CsclientPolicy -identity RedmondCommonPhoneClientPolicy -EnableClientMusicOnHold 1