ITU-T Q.553-1989 标准详情
- 标准号：ITU-T Q.553-1989
- 中文标题：
- 英文标题：transmission characteristics at 4-wire analogue interfaces of a digital exchange - digital local, transit, combined and international exchanges in integrated digital networks and mixed analogue-digital networks - supplements (study group xi) 12 pp
- 标准类别：国际电信联盟标准
- 发布日期：1989-01-01
