# ndInIoT-FC: IoT Devices as First-Class Traffic in Name Data Networks
## 2 Related Work  
The innovative concepts of ICNs, such as naming, named-based forwarding and in-network caching bring new benefits for content delivery but is not suitable for all types of network traffic. The basic ICN mode of operation, where one Interest is transmitted for each data packet requested, is not the best strategy for several communication models. Continuous flow traffic (media stream, sensor data gathering), disclosure of unsolicited information (alert message dissemination), and real time notifications present a strong tendency to cause an avalanche of Interest packets, and of course, the increase in the network overhead [6]. In IoT environments typical producer applications send small datasets of information each time. These datasets are consumed by some types of applications, such as dashboards in Cloud or alert systems. ICN natively support pull traffic (each Interest is served by a data package), but is not appropriated for data pushing. To address the requirements of these types of traffic some works proposed a publisher-subscriber model (pub-sub), where consumers can make _signatures_ of services to receive data without sending interests periodically [3]. The work in [7] classifies this type of traffic in single-request/multiple-response, periodic delivery, \(n\) responses and conditional delivery. In single-request/multiple-response a subscriber sends one request asking for data which may comprise of multiple responses spread over time. In periodic delivery consumers send one request packet asking for periodic data identified by name after a specific time interval. In \(n\) responses, subscribers nodes send one request packet for a specific number of responses, and in conditional delivery subscribers send a request packet to receive data from a publisher only if certain conditions are met or events triggered. Most of the work that implements pub-sub for ICN uses solutions based on _Persistent Interests_[8]. [PERSON] et al. [9; 10] improved and implemented the idea of Persistent Interests (PIs), and study their applicability in conversational services in NDN. They discussed the interplay of forwarding strategies and PIs in a way to improve the performance of the entire NDN. However, they compare the performance of PIs to the classical NDN approach using the network traffic generated by Internet telephony and do not discuss IoT environments. In [6] two extensions to CCN's routing and forwarding for disseminating information represented as channels and real-time documents were presented. They combine PIs and Reliable Notifications to efficiently support these traffic types. [PERSON] et al. [11] extended their previous work (COPPS [12]) with a lightweight implementation of pub-sub for IoT devices in NDN environments. The solution, called COPSS-lite, was developed to enhance CCN-lite [13] and also support multi-hop connection by incorporating the RPL protocol for low power and lossy networks [14]. However, such solution violates the loose coupling principle in their use of name-based routing or forwarding. In [15], the authors discuss how NDN can support reliable push-based IoT traffic, through the definition of three strategies to ensure reliable data pushing between consumers and producers: Interest notification; unsolicited Data, and virtual Interest polling. They also propose a simple analytical framework that provides preliminary quantitative insights into the proposed solutions. However, the presented study, used as proof-of-content, focused on a single consumer-producer pair, at one-hop distance. The work in [16] describes the potential of NDN in fog computing in smart environments, introducing a service orchestration mechanism targeted at a user-centric policy which values how the consumers perceive the services in terms of processing time as opposed to traffic in the edge domain. The solution proposed supports decisions of whether IoT data can be processed at the edge or remotely in cloud in a distributed manner.