ETSI PRETS 300 185-1991 综合业务数字网(ISDN).会议呼叫,追加(CONF)补充业务.数字用户1号信令(DSS1)协议(T/S46-33J1)
Integrated Services Digital Network (ISDN); Conference Call Add-on (CONF) Supplementary Service Digital Subscriber Signalling System No. One (DSS1) Protocol (T/S 46-33J1)