In this chapter, we provide a technical overview of cloud DCs and their network infrastructure evolution and discuss how SDN has emerged as a prominent technology for configuring and managing large-scale complex networks in this space. After comparing and contrasting the most common DC network topologies (such as canonical and fat tree, B-cube, DCell, etc.), we discuss the main challenges that SDN can help addressing due to, among others, the fast and flexible deployment of advanced services it can facilitate, its inherent programmability, and its suitability for supporting measurement-based resource provisioning. We subsequently describe the benefits of using SDN for DC network configuration and management and briefly outline some prominent SDN deployments over large-scale DCs. We discuss the potential of SDN to play the role of the central nervous system for the converged management of server and network resources over single-administrative DC environments and, finally, we highlight promising open issues for future research and development in this area.

Chapter Contents:

• 4.1 Overview
• 4.2 Cloud data centre topologies
• 4.2.1 Conventional architectures
• 4.2.2 Clos/Fat-Tree architectures
• 4.2.3 Server-centric architectures
• 4.2.4 Management network
• 4.3 Software-defined networks for cloud data centres
• 4.3.1 Challenges in cloud DC networks
• 4.3.2 Benefits of using SDN in cloud DCs
• 4.3.2.1 Advanced services
• 4.3.2.2 Network programmability
• 4.3.2.3 Always-on measurement
• 4.3.2.4 Energy efficiency
• 4.3.3 Current SDN deployments in cloud DC
• 4.3.4 SDN as the backbone for a converged resource control plane
• 4.3.4.1 Network resource management
• 4.3.4.2 Network-agnostic server resource management
• 4.3.4.3 SDN-based converged server-network resource management
• 4.4 Open issues and challenges
• 4.4.1 Network function virtualisation and SDN in DCs
• 4.4.2 The future of network programmability
• 4.5 Summary
• Acknowledgements
• References

Inspec keywords: telecommunication network topology; computer network management; computer centres; software defined networking; cloud computing

Other keywords: central nervous system; cloud DCs; network infrastructure evolution; measurement-based resource provisioning; DC network configuration; cloud data centres; server management; SDN; network resources; DC network topologies; single-administrative DC environments; large-scale complex network management

Subjects: Computer communications; Network management; Computer networks and techniques; Communication network design, planning and routing