Hierarchical SDN for the hyper-scale, hyper-elastic data center and cloud

Abstract

With the explosive growth in the demand for cloud services, the Data Center and Data Center Interconnect have to achieve hyperscale and provide unprecedented elasticity and resource availability. The underlay network infrastructure has to scale to support tens of millions of physical endpoints at low cost; the virtualized overlay layer has to scale to millions of Virtual Networks connecting hundreds of millions of Virtual Machines (VMs) and Virtualized Network Functions (VNFs), and provide seamless VM and VNF mobility.In this paper, we present Hierarchical SDN (HSDN), an architectural solution that achieves hyper scale using surprisingly small forwarding tables in the network nodes. HSDN introduces a new paradigm for the forwarding and control planes, in that all paths in the network are pre-established in the forwarding tables and the labels identify entire paths rather than simply destinations. These properties of HSDN dramatically simplify establishing tunnels, and thus enable optimal handling of both ECMP and anyto-any end-to-end TE, which in turn yields extremely high network utilization with small buffers in the switches. The preestablished tunnels make HSDN the ideal underlay infrastructure to enable seamless and lossless VM and VNF overlay mobility, and achieve excellent elasticity.HSDN is suitable for a full SDN implementation, using a scalable SDN controller to configure all forwarding tables in the network nodes and in the endpoints, as well as a hybrid approach, using conventional routing protocols in conjunction with a SDN controller.

Software‐defined networking (SDN): a survey

“…Several works have been proposed in this sense such as distributed controller architectures to dynamically rise or contract the controller pool according to network conditions where the traffic load is reapportioned among controllers . Other works focus on load‐balancing mechanisms or SDN hierarchical methods . For instance, in , an elastic distributed controller architecture is presented called ElastiCon that utilizes a dynamic adaptation of the controllers' number and their locations in the design of SDN to grow or shrink the controllers' pool depending on the network traffic load.…”

The Hierarchical Distributed Agent Based Approach to a Modern Data Center Management

“…It is necessary to use the cloud platform due to all advantages of the cloud computing and the growing number of workloads that are processed by cloud data centers [5,16]. OpenStack was chosen since it is the most popular cloud platform, it has the huge community, many commercial releases and, last but not least, it is opensource.…”

“…The number of hyperscale [5] data centers will continuously grow and will be doubled by 2020 [6]. These data centers will represent 47% of all installed servers by the same period.…”

Orchestration of End-to-End Network Services in the 5G-Crosshaul Multi-Domain Multi-Technology Transport Network

“…Per-vendor/pertechnology transport domains, each with its isolated control employing proprietary extensions, hinders the end-to-end (E2E) global management of transport networks. The concept of hierarchical distributed control of SDN networks has been proposed in the context of data centers [4] (as opposed to wide area network environments considered herein), mainly to pursue a high degree of scalability. In [5] and [6], preliminary design/architectural ideas behind the joint orchestration of wireless and optical transport domains and the initial characterization of part of this setup was presented.…”