BCN: Expansible network structures for data centers using hierarchical compound graphs

A fundamental challenge in data centers is how to design networking structures for efficiently interconnecting a large number of servers. Several server-centric structures have been proposed, but are not truly expansible and suffer low degree of regularity and symmetry. To address this issue, we propose two novel structures called HCN and BCN, which utilize hierarchical compound graphs to interconnect large population of servers each with two ports only. They own two topological advantages, i.e., the expansibility and equal degree. In addition, HCN offers high degree of regularity, scalability and symmetry, which well conform to the modular design of data centers. Moreover, a BCN of level one in each dimension involves more servers than FiConn with server degree 2 and diameter 7, and is large enough for a single data center. Mathematical analysis and comprehensive simulations show that BCN possesses excellent topology properties and is a viable network structure for data centers.