... lines for VoIP and PSTN switchLanguageEnglish,ChineseFunction Keys4 soft keys, 8 Line keys6 Navigation keys(Arrow ... ProcessingLine Status Indicator Multi AccountCall Waiting, Call Queuing, Line SwitchingCall Forward, Call Transfer, Call Holding, Call ... BLAExpansion InterfaceEXT: ESM32 programmable Key module*USB portApplicationSupport PSTN and VoIPPublic phone directoryPrivate phone directory* Built- ...