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For sipXecs 4.4 systems or higher, simply startup sipXecs and allow it to automatically migrate database
Voicemail can be copied from existing 4.2.1 server because xml file structure remained the same. Just make sure that user/group on all copied files is sipxchange:sipxchange.
All steps except number 6: "Migrate SCS database to sipXecs 4.2.1" I leave to you to figure out or find respective documentation on this wiki to detail.
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