It seems people sometimes have this view of SDN as addressing rather esoteric use cases and situations. However, the reality is that while there are instances of 'out there stuff' happening, there are many situations where we see customers leverage the technology to address pretty straightforward issues. And these issues are often similar across different business/vertical/customer types.

Aftab Rasool is Senior Manager, Data Center Infrastructure and Service Design Operations for Du.   I recently had the chance to talk with him about Cisco's flagship SDN solution -Application Centric Infrastructure (ACI) -and Du's experience with it. I found there were many instances of Du using ACI to simply make traditional challenges easier to deal with.

https://www.youtube.com/watch?v=n_yfj3trHNc&list=PLFT-9JpKjRTAB1jxPP0GT_PEdI6Hu32TQ&index=1

Du is an Information & Communications Technology (ICT) company based in Dubai. They offer a broad range of services to both consumer and business markets, including triple play to the home, mobile voice/data, and hosting. The nature of their business means the data center, and thus the data center network, is critical to their success. They need a solution to effectively handle challenges of both deployment, as well as operations...and that's where ACI comes in.

I'll quickly use the metaphor of driving to summarize the challenges Aftab covers in the video. He addresses issues that are both 'in the rear view mirror' as well as 'in the windshield' -with both being generalizable to lots of other customers. What I mean is that there are issues from the past that, though they are largely behind the car and visible in the mirror, still impact the driving experience. There are also issues on the horizon that are visible through the windshield, but are just now starting to come into focus and have effect.

Rear view mirror issues -These are concepts as basic as scalability associated with spanning tree issues, or sub optimal use of bandwidth, also due to spanning tree limitations. These issues are addressed with ACI, as there is no spanning tree in the fabric, and the use of Equal Cost Multi Pathing (ECMP)allows use of all links. Additionally, use of BiDi allows use of existing 10G fiber plant for 40G upgrades, thus obviating the expense and hassle of fiber upgrades. As a result, the ACI fabric, based on Nexus 9000's, provides all the performance and capacity Du needs.

Windshield issues -These are represented by a range of things that result from business's need for speed, yet are diametrically opposed by the complexity of most data centers. The need for speed through automation is becoming more and more critical, as is simplifying the operating environment, particularly as the business must scale. Within this context, Aftab mentioned both provisioning and troubleshooting.

Provisioning: Without ACI, provisioning involved getting into each individual switch, making requisite changes -configuring VLANs, L3, etc. It also required going into L4-7 services devices to assure they were configured properly and worked in concert with the L2 and L3 configurations. This device by device configuration not only was time consuming, but created the potential for human error. With ACI, these and other types of activities are automated and happen with a couple of clicks.

Troubleshooting: Before ACI, troubleshooting was complicated and time consuming, in part because they had to troll through each switch, look at various link by link characteristics to check for errors, etc. With ACI, healthscores make it easy and fast to pinpoint where the challenge is.

Please take a few minutes to check out what Aftab has to say about these, and other aspects of his experience with ACI at Du.