Optical data center networks (DCNs) are becoming
increasingly attractive due to their technological strengths compared
to traditional electrical networks. However, prior optical
DCNs are either hard to scale, vulnerable to single point of
failure, or provide limited network bisection bandwidth for many
practical DCN workloads.
To this end, we present WaveCube, a scalable, fault-tolerant,
high-performance optical DCN architecture. To scale, WaveCube
removes MEMS, a potential bottleneck, from its design. WaveCube
is fault-tolerant since it does not have single point of failure
and there are multiple node-disjoint parallel paths between
any pair of Top-of-Rack (ToR) switches. WaveCube delivers
high performance by exploiting multi-pathing and dynamic link
bandwidth along the path.
Our extensive evaluation results show
that WaveCube outperforms previous optical DCNs by up to
400% and delivers network bisection bandwidth that is 70%-
85% of an ideal non-blocking network under both realistic and
synthetic traffic patterns. WaveCube’s performance degrades
gracefully under failures—it drops 20% even with 20% links cut.
WaveCube also holds promise in practice—its wiring complexity
is orders of magnitude lower than Fattree, BCube and c-Through
at large scale, and its power consumption is 35% of them.