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Facebook, Google use SDN to boost data center connectivity

Internet content providers like Facebook and Google are already using SDN to improve hyperscale data center connectivity. But more could be done.

Massive traffic flows driven by growth in social networks, video and mobile data have created demand for clusters...

of hyperscale data centers in specific metro areas. Delivering networks to transport traffic between these data centers creates new requirements for metro optical gear in terms of scale, cost and the ability to easily provision, manage and reconfigure with SDN tools.

ICPs change data center connectivity requirements

The largest Internet content providers (ICPs), including Google, Facebook, Twitter, Amazon and Microsoft, have significantly changed the way hyperscale data centers are designed and operated. These ICPs build clusters of huge (super store-sized) data centers in metro areas with good access to Dark fiber and Internet connections. These data centers are highly virtualized and run on commodity-based components. A single search request often requires data access across server clusters and in between data centers. As a result, ICPs rely on 100 Gbps metro optical equipment to deliver traffic between their data centers over dark fiber.

Hyperscale data centers drive new metro optical requirements

ICPs want the ability to rapidly provision and scale capability in a data center context.

ICPs have different network requirements than the traditional buyers of optical equipment -- the largest telecom and cable providers. ICPs want the ability to rapidly provision and scale capability in a data center context (e.g., rack and stack). They also want to operate (and rapidly reconfigure) their optical network with tools like those they use in their data center operation (e.g., DevOps tools). ICPs require metro optical systems that are:

  • Modular, scalable and easily upgradable
  • High-density, high-capacity and low-power in a small form factor
  • Easy to deploy with end-to-end management
  • Compatible with DevOps tools and easy to program
  • Low cost per 100 Gbps link

Impact of SDN

Currently, the biggest impact of SDN has been on Layer 2/3 -- that is, switches and routers. The challenge is to bring the benefits of SDN -- programmability, dynamic control of traffic flows, and ease of service provisioning and management -- and apply them to the optical network.

For the optical network, suppliers typically provide a software layer that abstracts the complexity of the optical layer and presents an SDN-like interface to Layer 2/3 services. SDN controllers may also be deployed to provide centralized intelligence of traffic flows and the ability to reconfigure traffic as required.

For data center connectivity, IT staff requires open, standards-based software that provides the ability to program the network. These SDN tools enable workload mobility, dramatically simplifying provisioning and maximizing operational efficiency. ICPs need the ability to apply their own applications to the network to rapidly set up circuits, provide dynamic bandwidth, optimize route selection and deliver fast restoration.

Metro optical data center systems on tap

A number of suppliers have introduced new metro optical systems designed to provide scalable data-center-to-data-center connectivity in the metro. These systems provide scalable 100 Gbps connectivity and associated SDN management software to meet the growing needs of their ICP customers. A few examples of this equipment include:

  • Cyan -- N Series and Blue Planet SDN software
  • Infinera -- Cloud Express and OTS software
  • Ciena – Coherent Select with integrated software intelligence

Other suppliers with interesting optical platforms include BTI, Cisco, Coriant, Alcatel-Lucent, Adva and Fujitsu.

ICPs require optical interconnections that enable them to flexibly link data centers together, creating one seamless resource. The network architecture must be modular and designed to enable rapid, massive increases of scale. Optical systems need to be easy to install and operate and enable IT staff to develop custom software through open APIs.

Buyers of optical network infrastructure for metro data-center-to-data-center connectivity should select suppliers based on factors that include scalability of 100 Gbps links, cost, ease of installation and management, and open SDN software.

Next Steps

Learn how and where data center network fabric and SDN intersect

What is a software-defined data center?

Cisco: Data center traffic will triple between 2013 and 2018

This was last published in March 2015

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