The business case for SDN
Is now the right time to invest in this emerging technology?
The software-defined network (SDN) has been one of the biggest networking topics of the past year or two. The trend promises unheard-of network agility, as well as simpler network management. Despite this, precious few enterprises (with the exception of web-scale organisations) are seriously utilising SDN. That said, trailblazing organisations have begun to experiment with SDN, and are already seeing significant returns on their operations. Is now the time to make a business case for SDN?
Certainly, there’s interest in the trend in the Middle East, but according to Samer Ismair, MENA network consultant at Brocade Communications, organisations are still at the early stages of the learning curve. Even among early adopters of SDN, he says, organisations are still working out the applications for this emerging technology.
“Early adopters of SDN are currently investigating a wide range of applications and use cases that include network virtualisation, large-scale data centre infrastructure management, traffic engineering, and wide area network (WAN) flow management. SDN is still at a conceptual stage in this region. The growth in the SDN market will be driven by companies working towards solving existing problems with networks – security, robustness and manageability and by innovating new revenue generating services on network infrastructures,” he says.
“Ultimately, the goal is to provide a highly flexible, cloud-optimised network solution that is scalable within the cloud. In our view, this ‘new’ network will be powered by fabric-based architectures, which provide the any-to-any connectivity critical to realising the full benefits of SDN. These include network virtualisation, programmatic control of the infrastructure, automation and dynamic configuration, on-demand service insertion and pay-per-use, all through standards-based software orchestration tools. Cloud service deployment will be faster, data centre management will be simpler and network operation will be easier.”
Indeed, these benefits are well understood — the problem that most organisations have is working out how to realise these benefits. After all, there’s no point in achieving simplified operations that drive savings if the initial up-front cost is too great. What’s more, despite everything that it promises, it’s generally accepted that some businesses simply won’t benefit from SDN. This means that a serious analysis of the trend needs to be conducted before taking it further.
“The Middle East’s current early adopters of software-defined technology are largely private sector organisations with cultures of innovation. But in the future, it is likely that many organisations will move more vigorously in this direction. SMEs will have an easier transition than large enterprises, as SMEs can more rapidly virtualise their business critical applications,” explains Savitha Bhaskar, COO of Condo Protego.
“However, it is always important for organisations to ask themselves if software-defined technology is the right fit for them, as some organisations will adopt it immediately, while others may take longer. Cost can be a barrier for adopting new technologies such as software-defined data centres — as using non-specialised hardware has historically been the cheaper route. But today, the cost of specialised hardware solutions is only incrementally higher, making the decision of software-defined versus purpose-built a question of specific requirements, rather than price.”
Indeed, according to Cherif Sleiman, general manager for the Middle East at Infoblox, to get the maximum benefit from SDN, it would be good to have an Ethernet fabric network architecture in place. He says that, while SDN promises to solve a number of challenges for modern virtualised data centres, it does add complexity of a different sort. Both physical and overlay networks will now need to be managed, and currently, without visibility of one another.
“In order to take full advantage of the advantages of overlay networks, automation of basic tasks in the physical network therefore becomes critical. Ethernet fabrics are an evolutionary form of Ethernet that provide a flatter, highly available network architecture with some degree of automation,” he says.
Brocade’s Ismair agrees. Indeed, he goes one step further by explaining that SDN can only be effective when deployed on fabric networks. He says that fabrics resolve all the issues of the legacy, three-tier architecture, to provide the road a super-charged SDN solution needs to operate at optimal levels. Without this, he says that SDN will still ‘work’, but it will take longer, cost more, create additional levels of complexity and won’t deliver the business benefits you might hope for.
“In traditional Ethernet networks running spanning tree protocol (STP), only 50% of the links are active while the rest act as backups in case the primary connection fails. Ethernet fabrics provide active always-on connectivity, an ideal basis for a software-defined network. Although fabrics work internally without STP, they manage to work with existing Ethernet networks and use STP instead of a self-aggregation of ISL connections between the connected ethernet fabric switches. Ethernet fabrics are self-monitoring and vendors now offer functionality for tracking health at the switch component level. In the event of an outage, links can be added or modified quickly and non-disruptively. This self-healing fabric approach doubles the utilisation of the entire network while improving resilience. It also allows IT architects to confidently increase the size of their Ethernet networks, which helps make virtual machine (VM) mobility much more feasible,“ he says.