GEANT uses the Infinera DTN-X equipment to light our fibre. This equipment is built around 500 Gbps super channels on the fibre between GEANT's on-net PoPs. Unlike ROADM based DWDM equipment, the DTN-X disaggregates the client and trunk interfaces and all traffic passes through an central OTN switching core. This allows all services to be managed using a GMPLS control plane operating at the OTN layer. This architecture makes the addition of an SDN API to the DTN-X network a relatively straight-forward process. Infinera has been actively promoting their Open Transport Switch (OTS) concept which allows end-to-end services to be built via a restful interface. In this presentation I will discuss the OTS trials that GEANT have performed over the 6 months leading up to TNC16. I will go on to present an overview of GÉANT’s plans for the evolution towards incorporating the DTN-X equipment into the GEANT SDN architecture, with a particular focus on multi-layer integration. I will discuss our work on using Corsa SDN switches to deliver SDN-IP in the GEANT network and how a single SDN controller can be used to deliver multi-layer integration.