NF Z66-393-1993
信息系统互连.ISDN.在OSI连接模式网络服务上使用ISDN电路模式64 kbit/s无限制载体服务的OSI连接模式传输服务的规定.需求情况
Information systems interconnection - ISDN - Provision of OSI connection-mode transport service over the OSI connection-mode network service by using an ISDN circuit-mode 64kbit/s unrestricted bearer service-Demand case