When deploying and developing Infrastructure as a Service or Database as a Service like solutions within your datacenter you are most likely will be hitting a number of issues. When deploying aaS like cloud services you do have a desire to build this as automated as possible and to ensure rapid deployment and extension of your cloud infrastructure when needed. What often is a issue when you deploy your aaS solution in an existing datacenter is that the existing network teams and the existing network infrastructure are unable to cope with the speed and flexibility needed in a cloud concept.
A solution to this is the deployment of Software Defined Networking or short SDN. This can be embedded in the existing datacenter network infrastructure as an extension and give a cloud solution the flexibility that is needed. 
Oracle SDN redefines server connectivity by employing the basic concepts of virtualization. Unlike legacy port- and switch-based networking, which defines connectivity via complex LAN configurations, Oracle SDN defines connectivity entirely in software, using a supremely elegant resource: the private virtual interconnect. A private virtual interconnect is a software-defined link between two resources. It enables you to connect any virtual machine or server to any other resource including virtual machines, virtual appliances, bare metal servers, networks, and storage devices anywhere in the data center. Connect in seconds without inflexible network configuration, and gain the flexibility and agility you need in order to take control of your cloud.
Oracle SDN enables you to start with a small deployment and grow over time. It works with your existing 1GE, 10GE, and Fibre Channel switching infrastructure and is interoperable with virtually every x86 server, Oracle SPARC T-Series and M5 servers, including rack-and blade-based systems. As you grow, simply add new Oracle Virtual Networking components and connect them to build a fabric. You can start with a small number of servers and grow to a thousand.
When you are serious about deploying a cloud solution, a private cloud within your datacenter which requires a high level of agility and will deploy multiple types of services then SDN is something you will need to evaluate. If you use your cloud solution as a static consolidation cloud which will not change much over the coming time SDN might be overkill. 

For more information about this topic, feel free to contact Johan Louwers directly viajohan.louwers@capgemini.com