Making Constrained Things Reachable : A secure IP-agnostic NAT traversal approach for IoT

The widespread adoption of the Internet of Things (IoT) has created a demand for ubiquitous connectivity of IoT devices into the Internet.While end-to-end connectivity for IoT requires in practice IPv6, a vast majority of nodes in Internet are only IPv4-capable. To address this issue, the use of Network Address Translation (NAT) at the IoT network boundary becomes necessary. However, the constrained nature of the IoT devices hinders the integration of traditional NAT traversal architectures through IoT networks. In this article, we introduce a novel transition mechanism that transparently enables IoT devices behind NATs to connect across different network-layer infrastructures. Our mechanism adopts the IoT standards to provide a global connectivity solution in a transparent, secure, and elegant way. Additionally, we revisit the NAT solutions for IoT and describe and evaluate our current implementation.