... ISDN PRI, V5.2 signaling, can be programmed for all center and other value-added business. Feature:·Signaling support: SS7, ... CTI Link API interface for user program control· Conference call resources PABX function· Convenient and Flexible Coding: extension can set different ... prefix· Multiform new operation:Leave Transfer, Don't disturb, Call Protection, Transfer, Act for Pick-Up, ct for dialing, ...