Duplex negotiation over 100Base fibre

[jason+nanog at lixfeld.ca (Jason Lixfeld)]

Hello,

My understanding is that for 1G and 10G optical networks, there is no concept of half-duplex mode, but I?m unclear about half duplex in the 100M optical world.  Specifically, if I connect two 100Base-LX (or BX) transceivers together, is there a requirement for the controller(s on either side) to select between full or half duplex, either by static configuration, or auto-negotiation?

Thanks!