Specification :

Compete telephone function: internal and external adapter, external line substitute call, forced insertion, hang-up urging, call quit, call monitor, internal and external line reservation, PSTN, internal and external line holding, message transfer outsideComplete management system: internal and external grade limitation, external number restriction, password control, timing restriction, deposit real-time control, internal and external lines grouping, Ext. call control, etc.Complete Ext services: Manu class configuration, call transfer, busy transfer, no-answer transfer, call pickup, busy call-back, destination number replace, call ringing distinction; Ext. regular/non-regular wake-up, Ext. DND, Ext. malicious tracing, Ext bill inquiry, Ext SN, number & class inquiry, Ext. telephone recording, Ext call reminding, Ext. hang-up urging, Ext caller ID display, group call, etc. Hot-swap to all unit cards for easy maintenance Intelligent voice mailbox function for users guide during operation Caller ID recognition, caller number display (CND) for internal and external caller ID, DTMF compatible FSK, E1 relay signaling caller display Real-time billing control system, auto-cut for zero-deposit calls, preventing cost overruns Audio message and special telephone recording system Auto-diagnosis system, Auto/Manu diagnosis for any device fault, relay diagnosis for ring/2M maintenance, auto shut/open external lines; auto extension diagnosis for telephone extension opening or short circuit. Dual telephone desk and scheduling desk interfaces, supporting conference call, group call, one-button recording and hotline etc. IP phone function, multiple prefixes, single prefixes password shared Multiple numbers adoption on single machine for different operators access PC terminal and network control system, remote maintenance and cost inquiry through LAN, modem, the Internet or 2M interfaceExchange for 2000 lines of telephone