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SDN—Evolution in Carrier Ethernet

Aug 30, 2012
Sue Kim - gu
Sue Kim - gu About the author

Software Defined Networking (SDN) is the hottest new technology in networking. ONF member company Google is running its backbone network traffic on an SDN network built using OpenFlow. Nicira was acquired by ONF member company VMware for $1.26 billion to accelerate the adoption of network virtualization in the data center.

All this buzz about SDN had me thinking, is this technology only for the data center or does is mark the evolution in the next generation of telecommunications networks?  What does it mean to technologies like Carrier Ethernet?

Tsunami of data driving a new approach to networking

The growing tsunami of data driven by the growth in mobile phones and tablets, the emergence of BIG DATA, and the rise in machine-to-machine communications requires that we think about networking differently. As service providers roll-out new network services, they struggle with how to keep pace with growing consumer and business demand and how to grow their Average Revenue per User (ARPU) faster than costs.

Carrier Ethernet attempts to solve this problem by providing high-value-per-bit at a lower-cost-per-bit while maintaining the reliability and predictable performance required by traditional SONET/SDH networks. The next stage of Carrier Ethernet growth will come from cloud services and Carrier Ethernet interconnects, combined with virtualized network services. The cost advantages of Ethernet alone cannot keep pace with the uncontrollable demand for bandwidth combined with the emergence of on-demand network services.

In comes SDN

If the move to Ethernet alone can’t keep pace, what is the next evolutionary (or perhaps revolutionary) step in Carrier Ethernet?

The Carrier Ethernet industry is looking long and hard at SDN. A new approach to architecting networking equipment that fundamentally changes the way we design and build networks. SDN moves from the monolithic network equipment design based on custom silicon, a custom control plane, and tightly integrated network applications (services) to a modular, programmable, and distributed design (figure 1).

Figure 1: Network architecture transformation.


Network Architecture Transformation 300x191 png

The key to SDN is the decoupling of network control from traffic forwarding. Whether these network controllers are based on the OpenFlow® standard or a hybrid of legacy switching/routing alongside OpenFlow, the network intelligence is centralized and appears to applications and policy engines as a single logical switch, simplifying network design and operations.

Distributed traffic forwarders can be added as demand dictates, reducing costly oversubscription of network bandwidth. Moreover, the separation of the network services enables service providers to more quickly add new services without having to forklift networking devices.

SDN—What are the next steps?

SDN is a logical next step in the evolution of Carrier Ethernet. It provides a new mechanism for architecting networking equipment and network design that complements and co-exists with today’s Carrier Ethernet networks.

Because SDN is in its infancy, now is the time to experiment. Start by identifying high-value use cases such as:

  • Dynamically partitioning access points and cell radios based on different parameters, including carrier, usage, identity, device type at the mobile edge, enabling optimal use of spectrum, Wi-Fi, and Carrier Ethernet mobile backhaul links.
  • Pool compute and storage across geographically distributed data centers; connect with Carrier Ethernet transport using SDN to allocate optimal use of bandwidth.
  • Traffic steering for content management and distribution, providing granular routing of traffic based on a wide-range of parameters such as subscriber policy, application type, and cached asset.

As the tsunami of data grows, the emergence of SDN in carrier networks is inevitable. Only a fundamental change in how we architect networks can prepare us for the dynamic growth in communications in the coming decades.

--Sandy Orlando

Orlando is a high-tech marketing executive with extensive experience in developing winning business strategies for networking and virtualization companies. She has written about trends in carrier and enterprise networking and has spoken at data center and Ethernet conferences regarding the network transition to SDN.

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Sue Kim - gu