6. Challenges ahead

The SDN approach is certainly promising, but nonetheless raises questions linked to the characteristic complexity of the combined activation of several functions, exposure and negotiation of a service's parameters from production to operation.

This complexity raises, among other issues, the question of performance and scale factor, which are highly dependent on the nature of the service to be produced and the volume of traffic exchanged, particularly between the PDP and PEP components.

The availability of standard information models, unanimously adopted by manufacturers, is also a key factor in the adoption of SDN techniques.

The ability of these techniques to coexist with a conventional routing system that lacks the required SDN functions also remains problematic.