Private branch exchanges for connection to public switched telephone networks run by certain public telecommunication operators-Specification for the procedure for in-service observation of PBXs undergoing type approval
专用分支交换机 用于连接某些公共电信运营商运营的公共交换电话网络 正在进行型式认证的PBX在役观察程序规范
Specifies the assessment of PBXs against the integrity of service requirements in BS 6450-1:1983 and the observation of PBXs against appropriate Parts of BS 6450 under operational conditions.Cross References:BS 4778BS 6450:Part 1:Section 6.1Telecommunications Act 1984