Dear firend,
MA5680T/MA5683T/MA5608T can use the main control board to achieve local cascading, or use the GIU upstream board to achieve local cascading. Each GIU uplink board can provide 4 GE optical ports, using uplink or cascade, respectively, according to the demand to choose the number of cascade ports. If you need active and standby, you need to configure two GIU upstream boards.
Thanks