Fiber optic supertrunking has a well established place in larger CATV networks. Supertrunks have to be transparent to the signal quality and they have to have no impact on the system reliability of the total network. 60 dB video SNR has to be achieved and down times of less than one hour per year are desirable. AM on fiber cannot achieve these goals (yet). FM and digital with a 20 dB higher loss budget than AM and better inherent reliability are well suited for high transmission quality as well as for redundant supertrunk: topologies, achieving excellent system availability numbers.