A survey on multi-layer IP and optical Software-Defined Networks.

As Software-Defined Networks become more and more popular, they start to appear in various architectures. The most common utilization of SDN is to control the network in the electric layers, including OSI/ISO layers 2 and above. However, SDN can be used much further. Professionals and scientists noticed that combining management and control of many layers at the same time can provide benefits. At one point, SDN started to be envisioned for multi-layer networks.