The Internet of Things (IoT) aims for connecting Anything, Anywhere, Anytime (AAA). This premise brings about heterogeneity that creates connectiv-ity challenges. These challenges constitutes a serious obstacle to interoperability between things. Most existing approaches tackles the interoperability problem by avoiding heterogeneity with standards at runtime. While heterogeneity is an intrinsic feature of the IoT, there is a need for an approach that embraces it to connect AAA. In this paper we propose a model-based methodology to tackle the interoper-ability problem. It relies on a Domain-Specific Language (DSL) for a model-based specification of the network and a transformation process to generate the network artifacts from this specification. The principle consists of achieving interoperability at the model-level, then during a transformation process, ensuring that it is preserved in the low-level code. Adopting this methodology makes the engineering of the IoT more rigorous, prevents bugs earlier and saves time.