Cache “Less for More” in Information-Centric Networks

Abstract

Abstract. Ubiquitous in-network caching is one of the key aspects of information-centric networking (ICN) which has recently received widespread research interest. In one of the key relevant proposals known as Networking Named Content (NNC), the premise is that leveraging in-network caching to store content in every node it traverses along the delivery path can enhance content delivery. We question such indiscriminate universal caching strategy and investigate whether caching less can actually achieve more. Specifically, we investigate if caching only in a subset of node(s) along the content delivery path can achieve better performance in terms of cache and server hit rates. In this paper, we first study the behavior of NNC's ubiquitous caching and observe that even naïve random caching at one intermediate node within the delivery path can achieve similar and, under certain conditions, even better caching gain. We propose a centrality-based caching algorithm by exploiting the concept of (ego network) betweenness centrality to improve the caching gain and eliminate the uncertainty in the performance of the simplistic random caching strategy. Our results suggest that our solution can consistently achieve better gain across both synthetic and real network topologies that have different structural properties.Keywords: Information-centric networking, caching, betweenness centrality. IntroductionInformation-centric networking (ICN) has recently attracted significant attention, with various research initiatives (e.g.,[4] and COMET [5]) targetting this emerging research area. The main reasoning for advocating the departure from the current host-to-host communications paradigm to an information/content-centric one is that the Internet is currently mostly used for content access and delivery, with a high volume of digital content (e.g., 3D/HD movies, photos etc.) delivered to users who are only interested in the actual content rather than the source location. As such, we no longer need a natively supported content distribution framework. While the Internet was designed for and still focuses on host-to-host communication, ICN shifts the emphasis to content objects that can be cached and accessed from anywhere within the network rather than from the end hosts only. In ICN, content names are decoupled from host addresses, effectively separating the role of identifier and locator in distinct contrast to current IP addresses which are serving both purposes. Naming content directly enables the exploitation of in-network caching in order to improve delivery of popular content. Each content object can now be uniquely identified and authenticated without being associated to a specific host. This enables application-independent caching of content pieces that can be re-used by other end users requesting the same content. In fact, one of the salient ICN features is in-network caching, with potentially every network element (i.e., router) caching all content fragments 1 that traverse it; in this context, if a matching request is recei...

Information-Centric Networking: Evaluation and Security Considerations

“…Since ICN is an emerging area, the community is in the process of [Chai12], and hash-route-based caching [HASHROUT].…”

“…Based on this approximation and in order to reduce caching redundancy across the path, it caches content probabilistically. According to [Chai12], the node with the highest "betweenness centrality" along the path from source to destination is responsible for caching incoming content. Finally, [HASHROUT] calculates the hash function of a content's name and assigns contents to caches of a domain according to that.…”

“…Then, upon subsequent requests, and based again on the hash of the name included in the request, edge routers redirect requests to the cache assigned with the corresponding hash space. [HASHROUT] is an off-path caching strategy; in contrast to [Psaras12] and [Chai12], it requires minimum coordination and redirection overhead. In its latest update, Icarus also includes implementation of the "Satisfied Interest Table" (SIT) [Sourlas15].…”

Information-Centric Networking: Baseline Scenarios

“…In addition, Chai et al [CL4M] explore the benefits of ubiquitous caching throughout an information-centric network and argue that "caching less can actually achieve more." These papers also sit alongside a variety of other studies that look at various scenarios such as caching HTTP-like traffic [CCNCT] and BitTorrent-like traffic [BTCACHE].…”

ccnSim: An highly scalable CCN simulator

“…CS acts according to a caching decision policy (i.e., whether to store the data in CS or not) and a replacement policy (i.e., what to drop from CS in case it is full). While we already provide a fairly large number of decision (LCD [19], Random [13], LCE) and replacement policies (LRU, Random, FIFO) we have designed the CS in a modular fashion. Specifically, new replacement algorithms are implemented as modules overwriting the caching polymorphic methods store() and lookup(); a similar trick is done for new decisions policies with the polymorphic method isToCache().…”