4.4 A REST Interface for LonWorks

As we have seen in the previous section, a web services interface already exists for LonWorks. However, the new trend in M2M architecture is to use a REST model, where the types of interactions are restricted to only the CRUD1 verbs. This requires a specific design of the representation of the underlying M2M network or device.

Echelon Corporation published a first version of a REST interface for LonWorks in July 2010. In this version 1.0, the “LonBridge Proxy Server REST API” supports the basic CRUD REST interactions, but did not introduce yet a subscribe/notify model: this type of interaction is feasible in a REST architecture but requires both interface sides to act as client and server. Standardized subscribe/notify REST models have been introduced for instance by ETSI TC M2M (refer to Chapter 14 this book): it is expected that ETSI M2M interfaces to LonWorks will also exist in the near future, and introduce the additional interactions and features made possible by the ETSI TC M2M REST architecture.