The full command line would be as follows:
msiexec.exe /a CiscoUnifiedPersonalCommunicatorK9.msi /qn /lv C:\temp\CUPCSetup.log
You may omit the msiexec.exe if you choose not to use that options.
/a identifies the package name that I downloaded from Cisco. Note this is the MSI installer and not the EXE. The difference is .net frameworks is not installed using the MSI.
/qn This is quiet mode no dialog or anything from the user. This is stealth mode.
/lv logs verbose to the directory c:\temp\CUPCSetup.log You can check here in case of failures.
Setup Type: Windows Installer (MSI)
Deployment Method Used: Windows Installer Command Line (No MST)