A framework for the IPv6 based implementation of a reactive routing protocol in ns-3: Case study using LOADng

The lightweight on-demand ad hoc distance-vector - next generation (LOADng) is a reactive routing protocol proposed for low-power and lossy networks (LLNs). ITU-T G.9903 standard for power line communication specifies LOADng as its default routing protocol. LOADng establishes bidirectional routes and has routing mechanisms for unicast, multicast and broadcast packets. This paper discusses a general framework for the IPv6 based implementation of a reactive routing protocol in ns-3. The framework is then used to implement LOADng routing protocol in ns-3 as per the latest Internet-draft recommendation. Our implementation of LOADng module in ns-3 is useful to study the potentials and pitfalls of the protocol, to investigate the impact of the various protocol parameters, to derive some non-trivial insights into the protocol behavior, and to compare its performance with other routing protocols proposed for LLNs. Our implementation is flexible enough to be modified and augmented with new features. To reduce the control overhead, the Smart-RREQ concept is incorporated as an extension to the basic framework. Another important feature added to this basic module is the multipath capability. Performance improvements with these new features are verified. The module is also tested for its performance with different route metrics. The framework is useful for implementation of other reactive routing protocols in ns-3.