Should actually work, the FB doesn't care where the Ethernet signal comes from. The question is, however, whether the link converter works together with the fibre optic network, you would have to ask your provider (ask your system administrator - he doesn't know either, or throw the thing against the wall:-). And then there's the question of whether the provider really offers an All-IP connection via the fibre. For example, we have a Gugus system from GGA-Maur here where you need separate Ethernet distributions for telephony, Internet and TV, because they obviously don't manage to offer their customers a sensible All-IP connection. Of course, this complicates the distribution in the house enormously afterwards, otherwise you could bring everything to every place with an Ethernet hose. Unfortunately, we had to switch to this lousy provider because the previous provider who offered such connections had terminated the municipality's love. So probably first clarify whether it really is an all-IP connection, otherwise it can then become very complicated.