1. By checking the service configuration of the bound channels, we find the timeslots bound
at the two ends are consistent without any problem, and the ports are configured normally.
2. The EFP0 is used to transmit Ethernet frames locally over the existing PDH telecommunications networks, meeting the requirements of Ethernet service convergence. EFS0 don't support this scenario. so replace EFS0 and EFS4 with EFP0, then the service is finnally up.