The purpose of HA feature is to provide continuously operational VBVoice service. When the virtual machine running the RTM is moved, the new machine will be able to provide the same functionality.
In order to configure HA:
Edit vbvrtm.ini (ex> C:\Windows\vbvrtm.ini)
[Config]
; default 0 for the full MachineID
UseBasicMachineID=1