Brocade MAPS came with same on a IBM TapeLib TS4300 drive
At a sudden stage , the port came in status SYNC
Cleaned cable ends, wired another cable, reconfigured the port & Tapedrive with fixed speed 8gb & N-port (instead of mixed N/Loop mode) on drive side but it had no impact
I swapped cables among TapeDrives (there are 2 inside) and the problem remained on the underneath tapedrive.
I decided to reset the Tdrive and after that the Tdrive correctly logged in and status is ONL
I regot 2 reccocurances. Decided to clean the whole path.
Used my netfluke IBC cleaner 1.25 mm for the cable & the IBC Cleaner MPO for the tapdrive ports, PP ports (Tapeside & switchside)
Not a single enc out event after 4 days.