Efficient Hash-routing and Domain Clustering Techniques for Information-Centric Networks

Abstract

Hash-routing is a well-known technique used in server-cluster environments to direct content requests to the responsible servers hosting the requested content. In this work, we look at hash-routing from a different angle and apply the technique to Information-Centric Networking (ICN) environments, where in-network content caches serve as temporary storage for content. In particular, edge-domain routers re-direct requests to in-network caches, more often than not off the shortest path, according to the hash-assignment function. Although the benefits of this off-path in-network caching scheme are significant (e.g., high cache hit rate with minimal co-ordination overhead), the basic scheme comes with disadvantages. That is, in case of very large domains the off-path detour of requests might increase latency to prohibitive levels. In order to deal with extensive detour delays, we investigate nodal/domain clustering techniques, according to which large domains are split in clusters, which in turn apply hash-routing in the subset of nodes of each cluster. We model and evaluate the behaviour of nodal clustering and report significant improvement in delivery latency, which comes at the cost of a slight decrease in cache hit rates (i.e., up to 50% improvement in delivery latency for less than 10% decrease in cache hit rate compared to the original hash-routing scheme applied in the whole domain).

Information-centric mobile caching network frameworks and caching optimization: a survey

“…In order to deal with extensive delivery latency, an ICN based networking method integrated with hashrouting and domain clustering techniques is presented in [28]. The network is represented as a graph which consists of the sets of routers and communication links and each node of the graph enables to cache and forward a request to corresponding caching nodes.…”

“…The metric of delay is discussed using optimization theory in [28,29,32,35,36] and game theory in [103]. Minimizing caching failure probability or maximizing caching hit rate are formulated in [33,34,53,62,104].…”

“…In [28], hash-routing and domain clustering techniques are applied to ICN environment of arbitrary topology, which aims to reduce the retrieval latency of ICN. In the network, when a request arrives, an edge router calculates the hash of the content identifier and forwards it to the responsible cache in the domain.…”

Neighborhood-Based In-Network Caching for Information-Centric Networks

“…Part of routers along a path can be properly selected according to a probability model [5] or graphbased metrics such as node degree and betweenness [6] [7]. In off-path caching, data contents are cached in a certain set of routers in the network and their locations are determined by a hash function [8]. A combination scheme which uses both on-path and off-path caching is also possible [9].…”

Low complexity content replication through clustering in Content-Delivery Networks

“…In [29] authors apply clustering to partition a network domain in sub-domains in an attempt to enable efficient hash routing techniques in the area of InformationCentric Networks. The aforementioned approaches are complementary to this work, given that our scheme relies on aggregating content items, neither users nor network nodes.…”