| 摘要 |
PROBLEM TO BE SOLVED: To provide a facility loopback method and an optical transmitter in an optical transmission system which can continuously perform LAPD communication even if the facility loopback is executed. SOLUTION: A Dccr extraction circuit 33 extracts a Dccr included in an overhead part and outputs it to a Deer communication protocol part 4. When execution of facility loopback is instructed, data after the Dccr is extracted are given to a Dccr insertion part 52 from the Dccr extraction circuit 33. The Dccr communication protocol part 4 analyzes a control message included in the Deer and prepares a response message corresponding to its control message. The Dccr including the control message is outputted to the Dccr insertion part 52. The Dccr insertion part 52 sets a new Deer in the data looped back the Dccr extraction part 3. |
