美利体育登录入口官网:ITU-T E.490.1-2003
通信工程建议概览 E系列:主题网络允许 电话服务 服务操作和人力因素 通信工程测量和通信记录
Overview of Recommendations on traffic engineering SERIES E: OVERALL NETWORK OPERATION TELEPHONE SERVICE SERVICE OPERATION AND HUMAN FACTORS Traffic engineering Measurement and recording of traffic