exchange

compete telephone function, internal and external adapter,external line substitute call,forced insertion,hang-up urging ,call quit ,call monitor ,internal and externalline reservation,PSTN,internal and external line holding

complete Ext. servies:manu clall configuration,call transfer,busy transfer,no-answer transfer ,call pickup,busy call back,destinaionnumber place ,call ringing .

intelligent voice mailbox function for users guide during operation

auto-diagnosis system

IP phone function ,multiple prefixes ,single prefixes password shared

multiple numbers adoption on single machine for different operators access