Network Aspects (NA); Numbering plans for the interconnection of virtual private networks and public networks
网络方面（NA）；虚拟专用网络和公共网络互连的编号计划

1992-07-01

Speech processing, Transmission and Quality aspects (STQ); Transmission characteristics of digital Private Branch eXchanges (PBXs) for interconnection to private networks, to the public switched network or to IP gateways
语音处理、传输和质量方面（STQ）；用于与专用网络、公共交换网络或IP网关互连的数字专用分支交换机（PBX）的传输特性

2000-10-01

Business Telecommunications (BT); Overall transmission plan aspects of a private branch network for voice connections with access to the public network
商业电信（BT）；用于接入公共网络的语音连接的专用分支网络的总体传输计划方面

1990-08-01