# ICN-Based Enhanced Content Delivery for CDN
## 3 Proposed Design
### Motivation  
Over the past few decades, CDN has evolved to demonstrate remarkable stability and high service performance. However, the inherent design of CDN often relies on a centralized set of content servers. On the contrary, ICN emphasizes more lightweight and ubiquitous caching. This motivation section explores the potential advantages of adopting ICN to complement the CDN architecture.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Approach** & **ICN Paradigm** & **Integration Method** & **Discussions** \\ \hline nCDN [31] & NDN & \begin{tabular}{c} An overlay method by setting \\ up NDN running over \\ UDP/TCP \\ \end{tabular} & \begin{tabular}{c} Provide better QoS, reliability \\ and scalability especially in \\ dynamic network \\ \end{tabular} \\ \hline R-iCDN [32] & \begin{tabular}{c} Not mentioned but \\ name-based routing \\ \end{tabular} & \begin{tabular}{c} Integrate a centralized content \\ routing engine in CDN, using \\ ICN name-based routing \\ \end{tabular} & \begin{tabular}{c} Improve CDN sub-optimal \\ routing in ISP networks \\ \end{tabular} \\ \hline CDN with NDN slice [33] & NDN & \begin{tabular}{c} Integrate NDN as a \\ network slice \\ \end{tabular} & \begin{tabular}{c} Shorten delivery time and \\ reduce traffic load by \\ leveraging ICN for regional \\ content distribution \\ \end{tabular} \\ \hline iCDN [34] & NDN & \begin{tabular}{c} Build CDN in NDN’s logic \\ using stateful forwarding \\ plane and in-network caches \\ \end{tabular} & \begin{tabular}{c} Using NDN technology on the \\ CDN full-mesh topology, \\ shorter delay and less traffic \\ load is achieved, FIB \\ explosion is avoided \\ \end{tabular} \\ \hline CDN over MobilityFirst [35] & MobilityFirst & \begin{tabular}{c} Build CDN on top of \\ MobilityFirst \\ \end{tabular} & \begin{tabular}{c} Combine the CDN application \\ awareness and ICN efficient \\ network forwarding \\ \end{tabular} \\ \hline IECDN proposed in this paper & \begin{tabular}{c} IP-compatible and \\ ID-based protocol \\ \end{tabular} & \
\begin{tabular}{c} ICN infrastructure service \\ layer with \\ translation gateways \\ \end{tabular} &
\begin{tabular}{c} Show reduced latency, less \\ overall bandwidth \\ consumption and better \\ resilience to traffic surge \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 1: Comparison of hybrid approaches in related work.  
1. Emphasis on lightweight and ubiquitous caching in ICN: ICN introduces a paradigm shift by emphasizing the lightweight nature of caching and embracing heterogeneous and ubiquitous caching capabilities. ICN nodes can seamlessly join and leave the network, offering great scalability and lower management costs. This departure from centralized caching servers brings better flexibility and failure resiliency.
2. Leveraging ICN for cost-efficient content delivery: One of the primary costs of CDN is from bandwidth consumption and maintenance. The ubiquitous caching capability of ICN allows for the storage of content replicas within the network at any place. Utilizing idle resources of ICN nodes, such as bandwidth and storage, to provide content service can reduce CDN deployment costs and enhance system scalability.
3. Benefits of the ICN cache relative to the CDN HTTP-based cache: In contrast to the CDN HTTP-based caching at the application level, the ICN cache operates at the network layer. The control overhead is minimized, involving only a few bits in the data packet for cache management. The ICN router can achieve line-speed caching operation. Furthermore, the ability of ICN to split content files into data chunks facilitates load balancing by distributing requests for locally popular content across multiple nodes.