Installation > Netzwerk Installation > Arbeitsplatz Setup verteilen > cdcoeconfig.dat - node [ClientConfigExt]:
InternalNumberPrefix
Prefix for internal number - see TAPI configuration
Default value: Empty
Page url: http://www.helpserver.biz/onlinehelp/cdc/oe/2.4/help2000/index.html?config_internalnumberprefix.htm