# Transparent CoAP Services to IoT Endpoints through ICN Operator Networks +
## 4 Design and Implementation
### Response Processing
Considering the IoT from ICN perspective, ICN research group (ICNRG) has involved in the activity of defining requirements and challenges of IoT over the existing ICN proposals [22; 23]. Several research efforts [24; 25; 26; 27; 28; 29; 30; 31] present the ICN framework in different IoT scenarios. In [24], the authors highlight the key challenges of IoT and provide a design of high level NDN architecture that can meet IoT challenges. In [25], the authors propose the Content-centric Networking (CCN) communication layer on top of MAC layer to transmit packets. Similarly, an overlay of ICN architecture based on CCN on top of ETSI machine-2-machine (M2M) architecture is presented in [26]. In [27], authors propose a service platform based on CCN for Smart Cities that can integrate the available relevant wireless technologies to provide ubiquitous services, optimize the usage of communication resources through distributed caching and provide security by exploiting the security feature of CCN architecture. In [28], the authors provide an experimental comparison of CCN with the traditional IP based IoT standards 6 LoWPAN/RPL/UDP in terms of energy consumption and memory footprint. This experiment used a compact version of CCNx [32], referred as CCN-Lite [33], in RIOT OS [34]. The authors of [29] propose a push mechanism for CCN to optimize the traffic in sensor networks, whereas authors of [35] propose a content-centric internetworking scheme for resource-constrained network devices based on task mapping where the network activities (e.g., storing, publishing, and retrieving content) of the constrained devices are transferred to the core CCN network. The work in [30] has designed and implemented a lightweight CCN protocol targeted for Wireless Sensor Network as an alternative to IP protocol for sensor network. All these efforts require modifications to IoT endpoints. In contrast, the POINT architecture provides a CoAP Handler that maps CoAP protocol onto appropriate named objects within the ICN core. Recent efforts [15; 16] have been performed on proxy based CoAP observe in Wireless Sensor Network (WSNs). [PERSON] et al. [15] includes WebSocket protocol in the design of the CoAP proxy for HTTP based web applications. The work in [16] considers dynamic aggregation/scheduling of multiple observe requests at CoAP proxies. These efforts are complementary to our work, which utilizes ICN to further enhance the efficiency gains of the CoAP observe. However, ICN-based approaches in IoT is still in early stage. The deployment of clean-slate ICN in IoT is a great challenge. The clean-slate ICN approach in IoT requires not only the re-design of networking protocols but also the modification of legacy Internet applications. Such radical changes to every network layer are an overwhelming barrier to the adoption of ICN. This paper focuses on an alternative approach which can be deploying ICN solutions as an overlay over the existing IP infrastructure so that ICN features can be exploited to improve the performance of the existing IP protocols in IoT. To achieve this, the paper emphasizes the design, implementation and evaluation of CoAP Handler which provides transparent CoAP services to IoT devices through an ICN core network. The is implemented by the Network Attachment Points (NAPs) that performs translations between the existing IP-based CoAP protocol and appropriately named objects within the ICN core on both edges of the core. In addition, we demonstrate the potential of how CoAP traffic over an ICN network can unleash the full potential of CoAP, shifting both overhead and complexity from the (constrained) endpoints to the ICN network. ## 7 Conclusions and Future Work

In this paper, we present the design and implementation details of the CoAP Handler for the POINT architecture that enable CoAP and CoAP extensions to IoT devices through ICN operator network. In addition, we demonstrate how ICN can benefit CoAP and its extensions, shifting both overhead and complexity from the CoAP endpoints to the ICN network.