Software-Defined Networking for data centre network management: A survey

Data centres are growing in numbers and size, and their networks expanding to carry larger amounts of traffic. The traffic profile is constantly varying, particularly in cloud data centres where tenants arrive, leave, and may change their resource requirements in between, and so the network configuration must change at a commensurate rate. Software-Defined Networking - programmatic control of network configuration - has been critical to meeting the demands of modern data centre network management, and has been the subject of intense focus by the research community, working in conjunction with industry. In this survey, we review Software-Defined Networking research targeting the management and operation of data centre networks

LogSnap: Creating snapshots of OpenFlow Data Centre Networks for offline querying

Software-Defined Networking (SDN) has enabled automated modification of the behavior of network devices to match changes in network policy. This facility has driven adoption of SDN in Data Centre Networks (DCNs), particularly multi-tenant DCNs, where network policies are used extensively and can change rapidly as tenants arrive, leave, and modify their resource usage. It is useful for a DCN operator to have a way to query the past state of a network, e.g. for debugging or verification. In a multi-tenant DCN whose behaviour changes frequently under the programmatic control of SDN, this is an important but complex function to provide. While SDN makes the problem more challenging, it also helps to provide the solution - changes in network policy are communicated in packets sent from an SDN controller to the network devices, and those packets are amenable to capture and analysis to reveal the state of the network. Our solution, LogSnap, records messages exchanged over time between an SDN controller and switches in a network, and can quickly recreate the network in an emulated environment for any point in the recorded history. We have evaluated the system for its accuracy, the speed with which it can recreate the network, and quantified the storage implications of speeding up network reproduction

ProActive routing in scalable data centers with PARIS

Modern data centers must scale to a large number of servers, while offering flexible placement and migration of virtual machines. The traditional approach of connecting layer-two pods through a layer-three core constrains VM placement. More recent 'flat' designs are more flexible but have scalability limitations due to flooding/broadcasting or querying directories of VM locations. Rather than reactively learn VM locations, our PARIS architecture has a controller that pre-positions IP forwarding entries in the switches. Switches within a pod have complete information about the VMs beneath them, while each core switch maintains complete forwarding state for part of the address space. PARIS offers network designers the flexibility to choose a topology that meets their latency and bandwidth requirements. We evaluate our PARIS prototype built using OpenFlow-compliant switches and NOX controller. Using PARIS we can build a data center network that supports up to 100K servers