# ICN-Based Enhanced Content Delivery for CDN
## 1 Introduction  
For the past few decades, the development of the internet has always adhered to the tenet of connecting a computer to another by establishing host-to-host communication. However, with the evolving user interests and requirements comes the boom of novel applications, such as Instagram and TikTok, which puts the nature of the internet under question. According to Cisco's 2020 annual report [1], video and other applications are in enormous demand in today's home, and there will be significant bandwidth demands with the video application requirements in the future. This simply means the internet is shifting towards a content-oriented delivery network of video files. Many content providers use content delivery networks (CDNs) as a patch to the current IP network infrastructure in order to enhance the availability of content. For example, Netflix has used services from both Akamai and Limelight to build an ISP-independent content delivery network [2]. A CDN caches content on edge servers in point-of-presence (POP) locations that are close to end users, thereby reducing access latency. When the user requests a file via a special domain name, the DNS routes the request to the optimal POP location, which is typically determined by geographic proximity. If no edge servers in the POP have cached the file, the file is retrieved from the origin server which is comparatively time consuming. Meanwhile, in the context of future internet study, many studies focus on a new networking paradigm called Information-Centric Networking (ICN). Contrary to the current IP network, ICN emphasizes the content itself rather than its location. The shift from a host-centric to content-centric communication paradigm facilitates the communicationbetween networking parties by the identifier of the content instead of the address of the host holding a copy of the content, which provides solutions to many issues faced by the IP infrastructure today. The design specifics of ICN paradigm have been proposed by many studies. Some of these research works advocate a clean-slate architecture, such as Content-Centric Networking (CCN) [3], Named Data Networking (NDN) [4] and Publish Subscribe Internet Technology (PURSUIT) [5]. However, many others acknowledge the unbearable cost of kicking IP networks out of the game and settle for the coexistence with existing IP networks to achieve incremental deployments, such as Data-Oriented Network Architecture (DONA) [6], the Network of Information (NetInf) [7], MobilityFirst [8] and SEANet [9]. Despite the differences in design, all of these candidate ICN architectures share the fundamental principle of ubiquitous in-network caching. Since the very beginning of the proposition of ICN paradigm, numerous research fields have endeavored to leverage its striking feature of in-network caching to enhance their performance, such as Internet of Things (IoT) [10], vehicular networks [11], 5G networks [12] and IPFS [13]. The benefits that the ICN in-network caching brings are particularly similar to those of CDN [14]. Meanwhile, the effectiveness of in-network caching has already been proven by the commercial success of CDN. The ICN content-centric communication paradigm meets the CDN content-oriented service requirements. CDN has already been incorporating technologies to enmaciptes itself from the bounds of host-centric communication paradigm of IP networks, such as GeoDNS [15] and Anycast [16]. In that sense, we envision a future CDN architecture with the support of ICN infrastructure. We incorporate the ICN in-network caching as a service for CDN to further improve the content availability. The main contributions of this paper can be summarized as follows:  
* We design an enhanced content delivery network architecture by integrating the ICN in-network caching as a service. Furthermore, we provide details on the mechanisms for enabling collaboration between different communication paradigms within these two networks.