| 摘要 |
PROBLEM TO BE SOLVED: To make output ATM cells of both systems match each other without causing a momentary break of a main signal. SOLUTION: Synchronization control parts 50 and 80 are provided in STM/ ATM conversion devices 30 and 60 of a system 0 and a system 1, and their control parts 50 and 80 are connected by an inter-system signal line. At the time control parts 50 and 80, data stored in respective cell composition buffers 39-1..., 69-1... are in the state of the final bytes of an ALL payload in the units of the cell composition buffers through the inter-system signal line and the system 0 informs the system 1 of the number of a cell composition buffer to be synchronized in the timing of the sequence number value of a previously decided ALL header. The stand-by system informed of the number starts inputting STM data to the cell composition buffer from the STM data of a next STM frame. Consequently, the STM data storage states of the cell composition buffers of the systems 0 and 1 can be matched with each other without causing any momentary break of the main signal. |
