177 research outputs found

    Compact Oblivious Routing

    Get PDF
    Oblivious routing is an attractive paradigm for large distributed systems in which centralized control and frequent reconfigurations are infeasible or undesired (e.g., costly). Over the last almost 20 years, much progress has been made in devising oblivious routing schemes that guarantee close to optimal load and also algorithms for constructing such schemes efficiently have been designed. However, a common drawback of existing oblivious routing schemes is that they are not compact: they require large routing tables (of polynomial size), which does not scale. This paper presents the first oblivious routing scheme which guarantees close to optimal load and is compact at the same time - requiring routing tables of polylogarithmic size. Our algorithm maintains the polylogarithmic competitive ratio of existing algorithms, and is hence particularly well-suited for emerging large-scale networks

    Online Permutation Routing in Partitioned Optical Passive Star Networks

    Full text link
    This paper establishes the state of the art in both deterministic and randomized online permutation routing in the POPS network. Indeed, we show that any permutation can be routed online on a POPS network either with O(dglogg)O(\frac{d}{g}\log g) deterministic slots, or, with high probability, with 5cd/g+o(d/g)+O(loglogg)5c\lceil d/g\rceil+o(d/g)+O(\log\log g) randomized slots, where constant c=exp(1+e1)3.927c=\exp (1+e^{-1})\approx 3.927. When d=Θ(g)d=\Theta(g), that we claim to be the "interesting" case, the randomized algorithm is exponentially faster than any other algorithm in the literature, both deterministic and randomized ones. This is true in practice as well. Indeed, experiments show that it outperforms its rivals even starting from as small a network as a POPS(2,2), and the gap grows exponentially with the size of the network. We can also show that, under proper hypothesis, no deterministic algorithm can asymptotically match its performance

    The efficiency of greedy routing in hypercubes and butterflies

    Get PDF
    Includes bibliographical references (p. 24-26).Cover title. "October 1990".Research supported by the ARO. DAAL03-86-K-0171 Research supported by the NSF. ECS-8552419by George D. Stamoulis and John N. Tsitsiklis

    Deadlock-free routing in a faulty hypercube

    Get PDF
    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 41-42).by Eric Lehman.M.S

    Optimal Oblivious Permutation Routing in Small Hypercubes

    Get PDF
    For each d <= 8 we provide an oblivious algorithm for routing any permutation on the d-dimensional hypercube in at most d communication steps. To prove our result we show that any 1-to-2 d' -routing problem and any 2 d' -to-1-routing problem can be solved in at most d' (d' <= 4) communication steps on a d'-dimensional hypercube. Furthermore we present a class of efficiently working routing algorithms which allows us to make an improved statement about the complexity of some of the provided algorithms
    corecore