An Experimental Investigation of Hyperbolic Routing with a Smart Forwarding Plane in NDN

Routing in NDN networks must scale in terms of forwarding table size and routing protocol overhead. Hyperbolic routing (HR) presents a potential solution to address the routing scalability problem, because it does not use traditional forwarding tables or exchange routing updates upon changes in network topologies. Although HR has the drawbacks of producing sub-optimal routes or local minima for some destinations, these issues can be mitigated by NDN's intelligent data forwarding plane. However, HR's viability still depends on both the quality of the routes HR provides and the overhead incurred at the forwarding plane due to HR's sub-optimal behavior. We designed a new forwarding strategy called Adaptive Smoothed RTT-based Forwarding (ASF) to mitigate HR's sub-optimal path selection. This paper describes our experimental investigation into the packet delivery delay and overhead under HR as compared with Named-Data Link State Routing (NLSR), which calculates shortest paths. We run emulation experiments using various topologies with different failure scenarios, probing intervals, and maximum number of next hops for a name prefix. Our results show that HR's delay stretch has a median close to 1 and a 95th-percentile around or below 2, which does not grow with the network size. HR's message overhead in dynamic topologies is nearly independent of the network size, while NLSR's overhead grows polynomially at least. These results suggest that HR offers a more scalable routing solution with little impact on the optimality of routing paths

A many-analysts approach to the relation between religiosity and well-being

The relation between religiosity and well-being is one of the most researched topics in the psychology of religion, yet the directionality and robustness of the effect remains debated. Here, we adopted a many-analysts approach to assess the robustness of this relation based on a new cross-cultural dataset (N=10,535 participants from 24 countries). We recruited 120 analysis teams to investigate (1) whether religious people self-report higher well-being, and (2) whether the relation between religiosity and self-reported well-being depends on perceived cultural norms of religion (i.e., whether it is considered normal and desirable to be religious in a given country). In a two-stage procedure, the teams first created an analysis plan and then executed their planned analysis on the data. For the first research question, all but 3 teams reported positive effect sizes with credible/confidence intervals excluding zero (median reported β=0.120). For the second research question, this was the case for 65% of the teams (median reported β=0.039). While most teams applied (multilevel) linear regression models, there was considerable variability in the choice of items used to construct the independent variables, the dependent variable, and the included covariates

A Many-analysts Approach to the Relation Between Religiosity and Well-being

The relation between religiosity and well-being is one of the most researched topics in the psychology of religion, yet the directionality and robustness of the effect remains debated. Here, we adopted a many-analysts approach to assess the robustness of this relation based on a new cross-cultural dataset (N = 10, 535 participants from 24 countries). We recruited 120 analysis teams to investigate (1) whether religious people self-report higher well-being, and (2) whether the relation between religiosity and self-reported well-being depends on perceived cultural norms of religion (i.e., whether it is considered normal and desirable to be religious in a given country). In a two-stage procedure, the teams first created an analysis plan and then executed their planned analysis on the data. For the first research question, all but 3 teams reported positive effect sizes with credible/confidence intervals excluding zero (median reported β = 0.120). For the second research question, this was the case for 65% of the teams (median reported β = 0.039). While most teams applied (multilevel) linear regression models, there was considerable variability in the choice of items used to construct the independent variables, the dependent variable, and the included covariates

Efficient FIB caching using minimal non-overlapping prefixes

The size of the global Routing Information Base (RIB) has been increasing at an alarming rate. As a direct effect, the size of the global Forwarding Information Base (FIB) has experienced rapid growth. This increase raises serious concerns for Internet Service Providers (ISPs) as the FIB memory in line cards is much more expensive than regular memory modules, so frequently increasing this memory capacity for all the routers is prohibitively costly to an ISP. Previous research on Internet traffic indicates that a very small number of popular prefixes receive most of the Internet\u27s traffic, making caching a possible solution to reduce the FIB size. However, FIB caching may cause a cache-hiding problem where a packet\u27s longest-prefix match in the cache differs from that in the full FIB, and thus the packet will be forwarded to the wrong next hop. Motivated by these observations, we propose an efficient FIB caching scheme that stores only non-overlapping FIB entries into the fast memory (i.e., a FIB cache), while storing the complete FIB in slow memory. Our caching scheme achieves a considerably higher hit ratio than previous approaches while preventing the cache-hiding problem. It can also handle cache misses, cache replacement, and routing updates efficiently. Moreover, we have implemented the proposed caching scheme using the OpenFlow platform, which allows a local or remote route controller to manage routes in the cache. We use real traffic of a regional ISP and a Tier1 ISP to carry out our experiments. Our simulation results show that with only 20 K prefixes in the cache (5.28% of the actual FIB size), the hit ratio of our scheme is higher than 99.95%. Our OpenFlow implementation achieves a hit ratio near 99.94%, which approaches the performance of the simulated results

Scalable name-based data synchronization for named data networking

In Named Data Networking (NDN), data synchronization plays an important role similar to transport protocols in IP. Many distributed applications, including pub-sub applications such as news and weather services, require a synchronization protocol where each consumer can subscribe to a different subset of a producer\u27s data streams. However, existing Sync protocols support only full-data synchronization, which is a special case of this problem. We propose PSync to efficiently address different types of data synchronization. Names are used in PSync messages to carry producers\u27 latest namespace information and each consumer\u27s subscription information, which allows producers to maintain a single state for all consumers and enables consumers to synchronize with any producer that replicates the same data. We have implemented PSync in the NDN codebase and used it to develop a prototype pub-sub module for building management. Our experimental results show that PSync scales well as the number of consumers, subscriptions, and data streams increases and it outperforms the state-of-the-art Sync protocol in supporting full-data synchronization

A Secure Link State Routing Protocol for NDN

The Named-data Link State Routing protocol (NLSR) is a protocol for intra-domain routing in Named Data Networking (NDN). It is an application level protocol similar to many IP routing protocols, but NLSR uses NDN\u27s interest/data packets to disseminate routing updates, directly benefiting from NDN\u27s built-in data authenticity. The NLSR design, which was first developed in 2013 and deployed on the NDN test bed in August 2014, has undergone significant changes. Following an application-driven design approach, NLSR\u27s development helped drive the development of the trust/security functionality of NDN libraries as well as a number of features in NDN\u27s forwarding daemon and ChronoSync. In this paper, we describe the current design and implementation of NLSR, with emphasis on those features that differentiate it from an IP-based link state routing protocol: 1) naming: a hierarchical naming scheme for routers, keys, and routing updates; 2) security: a hierarchical trust model for routing within a single administrative domain; 3) routing information dissemination: using ChronoSync to disseminate routing updates; and 4) multipath routing: a simple way to calculate and rank multiple forwarding options. Although NLSR is designed in the context of a single domain, its design patterns may offer a useful reference for future development of inter-domain routing protocols

Advanced Scientific Computing Research Network Requirements Review: Final Report 2015

The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the U.S. Department of Energy Office of Science (SC), the single largest supporter of basic research in the physical sciences in the United States. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 25 years. In April 2015, ESnet and the Office of Advanced Scientific Computing Research (ASCR), of the DOE Office of Science, organized a review to characterize the networking requirements of the programs funded by the ASCR program office. Several key findings resulted from the review - they are discussed in this report, along with the case studies presented at the review