| 1. | Tributary unit alarm indication signal tu - ais 支路单元告警指示信号 |
| 2. | Tributary unit loss of pointer tu - lop 支路单元指针丢失 |
| 3. | Tupp : tributary unit payload process 支路净荷处理 |
| 4. | Line unit and tributary unit 线路单元与支路单元 |
| 5. | Tributary unit pointer tu ptr 支路单元指针 |
| 6. | Tup : tributary unit pointer 支路单元指针 |
| 7. | Tug : tributary unit group 支路单元组 |
| 8. | Tributary unit group 支路单元组 |