On the Problem of Optimal Path Encoding for Software-Defined Networks

Adiseshu Hari; Urs Niesen; Gordon Wilfong

doi:10.1109/tnet.2016.2571300

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arXiv · 1507.07217

On the Problem of Optimal Path Encoding for Software-Defined Networks

Adiseshu Hari·Urs Niesen·Gordon Wilfong

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Abstract

Packet networks need to maintain state in the form of forwarding tables at each switch. The cost of this state increases as networks support ever more sophisticated per-flow routing, traffic engineering, and service chaining. Per-flow or per-path state at the switches can be eliminated by encoding each packet's desired path in its header. A key component of such a method is an efficient encoding of paths through the network. We introduce a mathematical formulation of this optimal path-encoding problem. We prove that the problem is APX-hard, by showing that approximating it to within a factor less than 8/7 is NP-hard. Thus, at best we can hope for a constant-factor approximation algorithm. We then present such an algorithm, approximating the optimal path-encoding problem to within a factor 2. Finally, we provide empirical results illustrating the effectiveness of the proposed algorithm.

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BibTeX RIS

Adiseshu Hari, Urs Niesen, Gordon Wilfong. 2016-05-19. On the Problem of Optimal Path Encoding for Software-Defined Networks. https://doi.org/10.1109/tnet.2016.2571300

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