NF Z82-049-1995
综合服务数字网络(ISDN).ISDN软件包方式载体服务(PMBS).用户存取D信道提供的ISDN虚拟呼叫(VC)和永久性虚拟呼叫(PVC)载体服务.基本速率和主速率
Integrated Services Digital Network (ISDN). ISDN packet mode bearer services (pmbs). ISDN virtual call (vc) and permament virtual call (PVC) bearer services provided by the D-channel of the user access. Basic and primary rate.