Hybrid Optical-Electrical Data Center Networking: Challenges and Solutions for Bandwidth Resource Optimization

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IEEE Communications Magazine


Fast optical switching (FOS) is the most promising technology for data center networks (DCNs) to meet data rate requirements beyond 800 Gb/s, considering its transparent modulation format, low power consumption and dense port integration. However, FOS, leveraging optical-packet-switching (OPS) technology, is hardly compatible with the electrical switches that are widely used in the current hybrid optical/electrical switching data center networks (Hoe-DCNs). The diversity of topologies and multi-switching granularity increases the risk of service disruption and reduces bandwidth efficiency. Based on the IPover- OPS system, we propose bandwidth resource optimization techniques with the aid of hybrid polling contention resolution and microsecond-level load balancing in Hoe-DCNs. We first present an optical switching architecture to show its performance characteristics in the context of nanosecond-level FOSs in terms of resource management and setup optimization. Based on the fabricated FOS structure, we discuss the emerging problem of packet contention and introduce a bufferless scheduling solution. The characteristics of load balancing for Hoe-DCN are then investigated and evaluated by simulating Hoe-DCNs. Finally, the numerical results are given and analyzed based on a large-scale DCN testbed. IEEE

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Bandwidth, Fabrics, Optical buffering, Optical device fabrication, Optical packet switching, Optical switches, Servers, Bandwidth resource, Data center networks, Electrical switching, Load-Balancing


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