SDDC takes data centre stage

Extended Feature Article:

The software defined data centre may be the promised land for providers struggling to deliver cloud services cost effectively at scale, but remains in the early stage of development.

Imagine a data centre uncluttered by legacy, dedicated network, server and storage hardware consolidated to the point where every application, service or process which can be delivered as a virtualised software function has been moved onto next generation architecture.

One that cuts time, cost and complexity out of the application and service provisioning overhead by centralising the administration and configuration of server, storage and network resources within a single console and allowing changes to be made automatically on the fly as and when the customer or workload requires them.

Many would argue it all sounds too good to be true, and even five years ago it seemed unlikely. But technology moves fast and the pace of development and innovation seen in software defined networking (SDN) and network function virtualisation (NFV) particularly means all bets are now off. Whereas server and storage virtualisation have long been widely deployed in data centres, SDN and NFV have only recently delivered the final component needed to turn the software defined data centre (SDDC) vision into a reality.

Simplified management and greater automation is key

Vendors and systems integrators now see an opportunity to give cloud providers, telcos, colos and other companies even more flexibility in how they provision propositions on an industrial scale across multiple hosting facilities using extended virtual overlays.

SDDC builds on the idea that virtualised compute, storage and network resources are grouped into portable workloads running on standard x86 servers and storage racks, interconnected by network switches and routers running open source operating systems and application programming interfaces (APIs) with no dedicated ASICs or proprietary command lined interfaces (CLIs) to handicap centralised configuration and management.

As such SDDC is perhaps not so much a paradigm shift, but an extension of the advantages SDN/NFV already offer. Namely simplified management and control of aggregated data centre resources and potentially lower operational costs from the elimination of unneeded hardware, and people, from the cloud service delivery equation.

Its prime benefit lies in bringing three previously separate areas of virtualisation – server, storage and networking – together under a single unified architecture which is tied more closely to individual application and service workloads, delivering greater flexibility in terms of provisioning, management and resilience than were possible if those three pools of virtualised resources were handled in isolation.

The big draw for data centre operators is better control and management – the ability to manipulate all three pools of resources from a single console screen (the much sought after but rarely seen single pane of glass).

But greater automation of the processes and transactions required to get virtualised workloads up and running is also a central part of the proposition, with automated provisioning managed by a framework of defined rules, policies and service level agreements, then passed by application programming interfaces (APIs) to an automation and orchestration engine which configures the appropriate resources from the aggregated pool.

Standardisation and definition

Inevitably at such an early stage of its development, the vision of the SDDC changes slightly from one vendor to another depending on which element of their own hardware and/or software portfolio they are looking to utilise. Performance optimised CPU architecture and solid state drives (SSDs) are expected to play a significant role in hosting virtualised network functions (VNFs), for example, as are virtualisation management and service orchestration platforms one reason why EMC, Intel and HPE are three of SDDC’s major proponents.

The closest anybody has come to laying down a definition for SDDC agreed by multiple vendors so far is the Distributed Management Task Force (DMTF), a framework which is very much a work in progress.

The not for profit trade association is currently working with chip makers, network equipment manufacturers, software companies and telcos – including Broadcom, Cisco, EMC, Fujitsu, Hitachi, Huawei, Intel, Microsoft, NetApp, VMWare and ZTE – to establish a clear definition and scope for the SDDC concept and develop suitable use cases, reference architectures and requirements to meet real world customer demand.


Barring a technology miracle it remains inconceivable that data centre hardware can ever be eliminated completely – the SDDC will still be built on a mixture of physical network, server, storage equipment. But the balance in that mix will change, with more applications, services, processes and transactions moving off dedicated, physical switches and routers and into server and storage architecture as virtualised software functions.

In many cases that could mean reductions in both capex on new hardware and opex on maintenance and management, with less engineers needed to install, configure and maintain specialised routers, switches or storage appliances based on proprietary architecture, unnecessarily complicated with their own CLIs and operating systems.

Staff costs remain a significant expense in any data centre budget, and more automation and self service provisioning may also lead to considerable cuts to the management overhead. So while SDDC may be little more than a twinkle in the eye for the majority of data centres now, it holds enough promise for service providers to be worth keeping an eye on.

SK Telecom takes interim step to SDDC

For the moment, anything resembling what people envisage an actual SDDC deployment will look like remains elusive, or at least a fiercely guarded secret. Even a famously forward thinking telco and cloud service provider like South Korea Telecom (SK Telecom), already a leader in SDN/NFV development and deployment, does not appear to be anywhere close.

But SK believes that SDDC will become an essential requirement for any telco or mobile operator engaged in fifth generation (5G) wireless network service provision, and is reported to be working with Intel to develop SDDC server platform.

As a precursor to the SDDC, SK has already built its simplified overlay networking architecture (SONA), which virtualises its data centre networks whilst simultaneously improving server connectivity, claiming that this approach will significantly reduce data centre construction costs and opex by the time 5G networks debut in 2020.

Proposed DMTF SDDC Standard: Core Requirements

  • Logical compute, network, storage and other resources
  • Discovery of resource capabilities
  • Automated provisioning of logical resources based on workload requirements
  • Measurement and management of resources consumed
  • Policy-driven orchestration of resources to meet workload service requirements

Written by Martin Courtney for Axians

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