The Physical Internet (PI, or $\pi$) concept was developed to address the current unsustainability problem of logistic systems. The key physical elements in the PI include $\pi$-containers, $\pi$-nodes, and $\pi$-movers. The $\pi$-containers designed to be world-standard, smart, green, and modular are moved, handled, and stored throughout an open global logistic infrastructure. Meanwhile, the $\pi$-nodes and $\pi$-movers including physical systems and vehicles are designed to exploit as best as possible the characteristics of $\pi$-containers. Thus, the logistics industry vision is a key player poised to benefit from the Internet of Things (IoT) revolution since millions of $\pi$-containers with contained shipments being moved, tracked, and stored by a variety of the $\pi$-nodes and $\pi$-movers each day. This paper propose a service-oriented architecture for IoT applied for the PI. A case study utilizing the architecture is presented to illustrate an efficient management service of logistics operations in the PI.