8.1.3. Service Information 
Audible Ringing on Rollover Lines is available on keysets having multiple
line appearances. It is configured on a per keyset basis.
The "signal when user is busy" option is provided via Administration
(AMO KCSU) to allow one of three rollover ring options, which is assigned
to each individual keyset to provide either -
No Ring when active on the telephone,
Alert Ring at the user selected rollover ring volume when active on
the telephone, or
Standard Ring at the user selected rollover ring volume when active
on the telephone.
Only line appearances which are assigned to audibly ring on the telephone
will be signaled when the user is active on the telephone.
An "Alert Ring" is a single short burst of ringing, sometimes
also called a "Splash Ring."
Phone setting default values (including Rollover Ring volume) are
administered via AMO ZAND, and individual phone settings (including Rollover
Ring volume) are administered via AMO ACTDA and via the user's phone
settings menu.