IP-optical convergence: a complete solution
Networks with separate IP and optical transport networks suffer from an unnecessary resource overhead, as each network has its own control and management mechanisms. In addition to the extra resources needed to reach a given performance target, separation also makes networks more complex than they need to be. Like many other issues that operators face today, this causes costs to rise and lowers the ability to evolve with changing business environments.

Authors: Stefan Dahlfort and Diego Caviglia
While some steps have been made to integrate the two transport networks, a fully integrated solution that includes logical integration of all planes – data, control, and management – is still needed.
For example, coherent technology combined with say flexible grid allocation, multi-rate transmitters/receivers – as part of elastic optical networks (EON) – and super-channels allows optical transmission systems to cope with increasing capacity demand without costly upgrades to the physical fiber network.
In addition to these operational benefits, IP-optical convergence puts DWDM optics directly onto router line cards, which is advantageous from a technical point of view, but also has a number of drawbacks.
So the questions that need to be answered are: when is it desirable or necessary to keep operations, and perhaps ownership of IP and optical transport separate, and when should they be integrated?
This Ericsson Review article outlines such a solution, which we refer to as IP-optical convergence.