SDN's promised advantages -- optimizing network resource usage,simplifying and accelerating service creation and enabling applications to specify resource requirements -- can also apply to optical transport networks. But first, SDN must be pushed beyond the ability to handle basic Ethernet infrastructure, and into the more diverse architectures of optical networks.
Transport networks were originally built to support long-distance voice traffic with high standards of reliability, but they were not meant to deal with highly dynamic capacity demands. Traffic was predictable with spikes at certain times of the day or the year.
But in the age of the cloud, providers distribute compute and storage resources around the world to provide 24/7 uptime in case some event causes one facility to shut down. Compute load is shifted from one cloud facility to remote facilities as demands outstrip local resources. Storage devices are backed up to remote facilities to protect against catastrophic loss. This wide distribution of resources has changed the demands placed on transport networks, making SDN an attractive alternative to current management technology.