Traditional networks had rather static architectures. Although they were permanently optimized in terms of stability and capacity, this did not necessarily render them more flexible. ROADM concepts offered first remedial options: Drag-and-drop functionality allows individual wavelengths to be coupled in or out without conflict of access, for very fast adjustment to meet new or changed requirements.
Virtual Networking uses open interfaces to take another huge stride in this respect: The optical network interacts with upper network layers and applications to adapt to specific requirements as and when needed. New routes will thereby be established dynamically and the network layout may be optimized in various directions – far easier than ever imagined on the optical level.