One day, a technician connected a client and informed me that the ONU is not registering with one of the BDCOM P3608-2TE EPON OLT. I looked at the logs:
enable show logging
And I saw the following message:
May 15 16:28:50 %OLT: LLID sequences have been used up on EPON0/4.
It means that all possible 64 LLIDs were used on this EPON port (64 ONUs already registered) and to solve the problem it is necessary to divide the trunk to enable it, for example, in two different EPON ports.
Fortunately, I looked at the signal graphs of the registered ONUs and found that there was one unknown ONU that had not been online for at least a year, so I just deleted it so that I could turn on a new client and the masters later divided the trunk slowly.