‘Unfair’ Discrimination in Two-sided Peering? Evidence from LINX

‘Unfair’ Discrimination in Two-sided Peering? Evidence from LINX Abstract: Does asymmetry between Internet Providers affect the “fairness” of their interconnection contracts? While recent game theoretic literature provides contrasting answers to this question, there is a lack of empirical research. We introduce a novel dataset on micro-interconnection policies and provide an econometric analysis of the determinants of peering decisions amongst the Internet Service Providers interconnecting at the London Internet Exchange Point (LINX). Our key result shows that two different metrics, introduced to capture asymmetry, exert opposite effects. Asymmetry in “market size” enhances the quality of the link, while asymmetry in “network centrality” induces quality degradation, hence “unfairer” interconnection conditions

A multipath analysis of biswapped networks.

Biswapped networks of the form $Bsw(G)$ have recently been proposed as interconnection networks to be implemented as optical transpose interconnection systems. We provide a systematic construction of $\kappa+1$ vertex-disjoint paths joining any two distinct vertices in $Bsw(G)$, where $\kappa\geq 1$ is the connectivity of $G$. In doing so, we obtain an upper bound of $\max\{2\Delta(G)+5,\Delta_\kappa(G)+\Delta(G)+2\}$ on the $(\kappa+1)$-diameter of $Bsw(G)$, where $\Delta(G)$ is the diameter of $G$ and $\Delta_\kappa(G)$ the $\kappa$-diameter. Suppose that we have a deterministic multipath source routing algorithm in an interconnection network $G$ that finds $\kappa$ mutually vertex-disjoint paths in $G$ joining any $2$ distinct vertices and does this in time polynomial in $\Delta_\kappa(G)$, $\Delta(G)$ and $\kappa$ (and independently of the number of vertices of $G$). Our constructions yield an analogous deterministic multipath source routing algorithm in the interconnection network $Bsw(G)$ that finds $\kappa+1$ mutually vertex-disjoint paths joining any $2$ distinct vertices in $Bsw(G)$ so that these paths all have length bounded as above. Moreover, our algorithm has time complexity polynomial in $\Delta_\kappa(G)$, $\Delta(G)$ and $\kappa$. We also show that if $G$ is Hamiltonian then $Bsw(G)$ is Hamiltonian, and that if $G$ is a Cayley graph then $Bsw(G)$ is a Cayley graph

Controllability Metrics, Limitations and Algorithms for Complex Networks

This paper studies the problem of controlling complex networks, that is, the joint problem of selecting a set of control nodes and of designing a control input to steer a network to a target state. For this problem (i) we propose a metric to quantify the difficulty of the control problem as a function of the required control energy, (ii) we derive bounds based on the system dynamics (network topology and weights) to characterize the tradeoff between the control energy and the number of control nodes, and (iii) we propose an open-loop control strategy with performance guarantees. In our strategy we select control nodes by relying on network partitioning, and we design the control input by leveraging optimal and distributed control techniques. Our findings show several control limitations and properties. For instance, for Schur stable and symmetric networks: (i) if the number of control nodes is constant, then the control energy increases exponentially with the number of network nodes, (ii) if the number of control nodes is a fixed fraction of the network nodes, then certain networks can be controlled with constant energy independently of the network dimension, and (iii) clustered networks may be easier to control because, for sufficiently many control nodes, the control energy depends only on the controllability properties of the clusters and on their coupling strength. We validate our results with examples from power networks, social networks, and epidemics spreading

Asymmetry and Discrimination in Internet Peering Evidence from the LINX

Is the quality of interconnection between Internet operators affected by their asymmetry? While recent game theoretic literature provides contrasting answers to this question, there is a lack of empirical research. We introduce a novel dataset based on Internet routing policies, and study the interconnection decisions amongst the Internet Service Providers (ISPs) members of the London Internet Exchange Point (LINX). Our results show that interconnection quality degradation can be significantly explained by asymmetry between providers. We also show that Competition Authorities should focus more on the role played by the “centrality of an operatorâ€, rather than on its market share.Internet Peering, Two-sided Markets, Network Industries, Antitrust, Net Neutrality