This chapter briefly introduces the data center network and reviews the challenges for future intra-data-center networks in terms of scalability, cost effectiveness, power efficiency, upgrade cost, and bandwidth utilization. Current data center network architecture is discussed in detail and the drawbacks are pointed out in terms of the above-mentioned parameters. A detailed background is provided that how the technology moved from opaque to transparent optical networks. Additionally, it includes different data center network architectures proposed so far by different researchers/team/companies in order to address the current problems and meet the demands of future intra-data-center networks.

Presently, research activities are geared towards optical switching technologies that involve all-optical switching, without transformation from optical domain to electronic domain. However, blocking in these systems is a huge problem due to the absence of appropriate optical buffers. In this paper, we propose an optical buffer design based on SOA and DCFBG (dispersion compensation fiber Bragg grating) for contention resolution in all-optically switched networks, and hence improved the power performance of the existing design.