YDN 124-1999
宽带综合业务数字网(B-ISDN)2号数字用户信令系统(DSS2)测试规范.用户接入控制部分(点一点)(内部标准)
Test spe4cifications for No.2 digital subscriber signaling system (DSS2) of broadband integrated service digital network (B-ISDN) Subscriber access control part (point-point) (internal standard)
