SDN changes data center architecture

Software-defined networking (SDN) is seen as having the long-term potential to fundamentally change data center architectures, but adoption and implementation rates remain low, with users concerned that SDN is an unproven or even overhyped technology.

Brad Casemore, research director of data center networks at IDC, said that there are many SDN standards and specifications in the industry, and technical experts and manufacturers are discussing the unification of standards, and it will take some time to finally determine the standards. The most important thing for people to remember is that, by its nature, SDN standards and specifications are driven by SDN developers, and the standardized framework that was mainly hardware-oriented in the past is not the best choice for this evolution.

“The old way of adopting IETF or IEE standards no longer works in this API software and device-driven world, and the IoT industry is still adapting,” he said.

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Software and Hardware

However, some analysts predict that SDN-enabled products will have a growing market share in the entire enterprise network in the future. According to IDC, by 2018, the market share of physical network infrastructure, controllers and network virtualization software, network and security services and related applications, and professional services with SDN capabilities will be approximately $8 billion, with an average annual compound growth rate (CAGR) of 89%.

The great potential of SDN lies in the ability to build a virtual network that covers the underlying network hardware, spanning multiple types and brands of switches, routers and other devices, decoupling software functions, allowing network managers to control and launch new network services and applications through network devices without having to touch physical hardware, and with the ability to implement them automatically.

SDN can effectively solve the problems of automated deployment and operation and maintenance of high-density and complex networks. On the other hand, computing virtualization technology also requires network virtualization, IP addresses, and the floating nature of network policies, which can also be solved in SDN applications.

But because SDN's software overlays the underlying network hardware, it no longer needs to be built into the operating system or a dedicated ASIC hardware driver. Physical processes and virtual switches can communicate directly through a central SDN controller, which can be implemented on basic "white box" switches or routers, or even on software-based virtual servers that run on the equivalent of x86.

Traditional networking vendors like Cisco, Juniper Networks, Extreme Networks, HP and others are understandably terrified of the power of SDN. People see a potential multi-billion dollar market for SDN, and the price of expensive, full-featured networking hardware is set to drop dramatically over the next decade. In response to SDN's momentum, all of these networking companies are embracing the technology in an effort to stay relevant and profitable in the long term. In some cases, open source SDN initiatives support interoperable SDN controllers that can manage any brand of equipment, while using different versions of the same code for other vendors' equipment, creating a competitive advantage by tightly integrating their open operating systems or physical hardware.

Clash of Giants

In fact, Casemore pointed out that there are two main alternatives in the next generation of data center networks currently being proposed. One is the data center market from network and storage hardware giants Cisco, EMC, and VMware, which have worked together to build the Virtual Computing Environment (VCE) platform. Cisco now spends $863 million to purchase this technology on the basis of providing application-centric infrastructure (ACI). The second is the NSX platform. In 2012, VMware invested $1.26 billion to acquire the NSX platform of its competitor Nicira.

Elsewhere, Juniper Networks has weighed in with its SDN controller and built-in features that allow third-party SDN controllers to manage virtualized networks on its hardware, among other products. HP has Helion, which is working on OpenStack, and Extreme Networks has launched an SDN platform based on its OpenDaylight controller. However, these incumbents face competition from new companies, such as Cumulus Networks, which is working with PLUMgrid to offer bare metal or white-box switches based on the Linux operating system on an OpenStack-based SDN platform.

Currently, SDN has been implemented in a single data center, and through wide area network (WAN) link bridging, it can extend the range of its host equipment for customers who need virtual networks. Casemore believes that SDN WAN will make data center equipment easier to manage for many companies compared to SaaS and cloud computing.

Nuage Networks is extending its virtual reach across telecommunications and cloud service provider networks with its Virtualized Service Assurance Platform (VSAP) host of IP and Ethernet WAN connections.

The biggest question is whether to add SDN software platforms and whether to enable SDN switches and routers to reduce expenses. Today, Cisco, Juniper Networks and other companies have put their SDN platforms into their customers' data centers.

David Logbau, marketing chief at service provider Juniper Networks, doesn't see it that way. Instead, he expects any gap in sales will be made up by data center expansion, as hosting companies add more ports through 10Gbit/s or 100Gbit/s upgrades or take existing switches and add higher-speed interfaces. "If you walk into a data center today, there's a quarter of space left for more servers," he said.

“The reason for the growth in the market is not from ripping and replacing old hardware, the more users invest in other layers of equipment, whether it’s top-of-rack switches, core networking or MPLS, the more new hardware they have and the more money they invest.”