30 research outputs found
The Role of Caching in Future Communication Systems and Networks
This paper has the following ambitious goal: to convince the reader that content caching is an exciting research topic for the future communication systems and networks. Caching has been studied for more than 40 years, and has recently received increased attention from industry and academia. Novel caching techniques promise to push the network performance to unprecedented limits, but also pose significant technical challenges. This tutorial provides a brief overview of existing caching solutions, discusses seminal papers that open new directions in caching, and presents the contributions of this special issue. We analyze the challenges that caching needs to address today, also considering an industry perspective, and identify bottleneck issues that must be resolved to unleash the full potential of this promising technique
Impact of Traffic Characteristics on Request Aggregation in an NDN Router
The paper revisits the performance evaluation of caching in a Named Data
Networking (NDN) router where the content store (CS) is supplemented by a
pending interest table (PIT). The PIT aggregates requests for a given content
that arrive within the download delay and thus brings an additional reduction
in upstream bandwidth usage beyond that due to CS hits. We extend prior work on
caching with non-zero download delay (non-ZDD) by proposing a novel
mathematical framework that is more easily applicable to general traffic models
and by considering alternative cache insertion policies. Specifically we
evaluate the use of an LRU filter to improve CS hit rate performance in this
non-ZDD context. We also consider the impact of time locality in demand due to
finite content lifetimes. The models are used to quantify the impact of the PIT
on upstream bandwidth reduction, demonstrating notably that this is significant
only for relatively small content catalogues or high average request rate per
content. We further explore how the effectiveness of the filter with finite
content lifetimes depends on catalogue size and traffic intensity