The Border Gateway Protocol (BGP), the de-facto Internet interdomain routing protocol, disseminates information about Internet prefixes to Autonomous Systems (ASes). Prefixes are announced and withdrawn as routes and policies change, making them unreachable from portions of the Internet for certain time periods. This paper aims to predict routing failures of prefixes in the Internet.We investigate the similarity of prefixes in the Internet with respect to their propensity to fail, i.e., become unreachable. Given a prefix of interest, we define a “BGP molecule” - the prefixes in the Internet that are likely to fail together with this prefix. We show that the AS paths to prefixes, coupled with knowledge of the prefix geographical location, contribute to its failure tendency. The BGP molecules constructed are used in four failure prediction schemes among which a hybrid scheme achieves 91% predictability of failures with 99.3% coverage of prefixes in the Internet.

The Border Gateway Protocol (BGP) maintains inter-domain routing information by announcing and withdrawing IP prefixes, possibly resulting in temporary prefix unreachability. Prefix availability observed from different vantage points in the Internet can be lower than standards promised by Service Level Agreements (SLAs). In this paper, we develop a framework for predicting long-term prefix availability, given short-duration prefix information from publicly available BGP routing databases. We compare three prediction models, and find that bagged decision trees perform the best when predicting for long future durations, whereas a simple model works well for short prediction durations. We show that mean time to failure and to recovery outperform past availability in terms of their importance for predicting availability for long durations. We also find that predictability is higher in the year 2009, compared to four years earlier. Our models allow ISPs to adjust BGP routing policies if predicted availability is low, and the models are useful for cloud computing systems, P2P, and VoIP applications.

The reachability of IP address prefixes exhibits significant fluctuations due to changes in both physical connectivity and ISP routing policies. In the late 1990s, Labovitz et al. performed an extensive study of inter-domain path stability by analyzing BGP routing data. To reduce the noise in the BGP data, e.g., transient updates during route convergence, they applied several filters to preprocess the raw BGP data. In this work, we investigate prefix reachability as advertised by BGP, while revisiting the preprocessing filter design problem. We show that the reachability analysis results are highly sensitive to the specific filters applied and the parameters that control the strength of the filters. In particular, we compute the mean time to failure and recovery (MTTF and MTTR) as well as the up- to-downtime ratios of prefixes, and find that these can fluctuate by a factor of 10 by varying the filter parameters. We analyze the impact of recent fiber cuts in the Mediterranean sea and the Middle East, and study prefix reachability during a nine-month period in 2007 to evaluate the general health of the Internet.

Data dissemination strategies and communication protocols that minimize the use of energy can significantly prolong the lifetime of a sensor network. Data-centric dissemination strategies seek energy efficiency by employing short metadata descriptions in advertisements (ADVs) of the availability of data, short requests (REQs) to obtain the data by nodes that are interested in it, and data transmissions (DATA) to deliver data to the requesting nodes. An important decision in this process is whether the DATA transmission should be made at full power in broadcast mode or at low power in multi-hop unicast mode. The determining factor is shown in this paper to be the fraction of nodes that are interested in the DATA, as shown by the number of REQs that are generated. Closed form expressions for this critical fraction of interested nodes is derived when the nodes have no memory or infinite memory for state information and when transmissions are reliable and not reliable. These results can be used during both the design and operation of the network to increase energy efficiency and network longevity

Multiple data-centric protocols - which can broadly be classified as push-pull, push-only, or pull-only - have been proposed in the literature. In this paper we present a framework to develop an insight into the characteristics of push-pull protocols. The performance of push-pull protocols is critically dependent on the timeout settings used to trigger failure recovery mechanisms. We perform a study of how to choose optimal timeouts to achieve best performance and use these timeouts to simulate and compare various push-pull protocols. Our starting point is a recently proposed SPIN-based protocol, called shortest-path minded SPIN (SPMS), in which meta-data negotiations take place prior to data exchange in order to minimize the number of data transmissions, thereby improving in both energy and delay compared to SPIN. We propose a redesign of SPMS, called SPMS-Rec, which reduces the energy expended in the event of failures by requiring intermediate relay nodes to try alternate routes. Our simulation results show that SPMS-Rec outperforms SPMS, and thus SPIN, yielding energy savings while reducing the delay when multiple nodes fail along a route. We further propose a modification to SPMS-Rec through request suppression which helps in reducing redundant data transmissions.