Architecture of network elements such as large routers and switches is becoming more and more complex due to the constantly increasing requirements on both capacity and performance. Already today, high-performance routers having capacities of more than several Tb/s can not be packaged in a single rack of equipment. Complex and spatially distributed multirack routers comprising a large number of line cards, switching modules and high-speed ports have already become reality. A consequence of this trend is that internal interconnecting system also becomes large and complex. Interconnection distances, total number of cables and power consumption increase rapidly with the increase in capacity, which can cause limitations in scalability of the whole system. This paper addresses requirements and limitations of large-scale optical interconnects. Various point-to-point interconnects and two optically switched interconnection options were studied with regard to their scalability by considering various impairments on optical signal, required number of fiber links and power consumption. Results of this study are presented and discussed in this paper.