Optimal Consistent Network Updates in Polynomial Time

  • Pavol Černý
  • Nate Foster
  • Nilesh JagnikEmail author
  • Jedidiah McClurg
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9888)


Software-defined networking (SDN) enables controlling the behavior of a network in software, by managing the forwarding rules installed on switches. However, it can be difficult to ensure that certain properties are preserved during periods of reconfiguration. The widely-accepted notion of per-packet consistency requires every packet to be forwarded using the new configuration or the old configuration, but not a mixture of the two. A (partial) order on switches is a consistent order update if updating the switches in that order guarantees per-packet consistency. A consistent order update is optimal if it allows maximal parallelism, where switches may be updated in parallel if they are incomparable in the order. This paper presents a polynomial-time algorithm for computing optimal consistent order updates. This contrasts with other recent results, which show that for other properties (e.g., loop-freedom and waypoint enforcement), the optimal update problem is np-complete.


Dependency Graph Outgoing Edge Correct Sequence Final Configuration Maximal Path 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Pavol Černý
    • 1
  • Nate Foster
    • 2
  • Nilesh Jagnik
    • 1
    Email author
  • Jedidiah McClurg
    • 1
  1. 1.University of Colorado BoulderBoulderUSA
  2. 2.Cornell UniversityIthacaUSA

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