On-Line Path Computation and Function Placement in SDNs

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10083)


We consider service requests that arrive in an online fashion in Software-Defined Networks (SDNs) with network function virtualization (NFV). Each request is a flow with a high-level specification of routing and processing (by network functions) requirements. Each network function can be performed by a specified subset of servers in the system. The algorithm needs to decide whether to reject the request, or accept it and with a specific routing and processing assignment, under given capacity constraints (solving the path computation and function placement problems). Each served request is assumed to “pay” a pre-specified benefit and the goal is to maximize the total benefit accrued.

In this paper we first formalize the problem, and propose a new service model that allows us to cope with requests with unknown duration without preemption. The new service model augments the traditional accept/reject schemes with a new possible response of “stand by.” We also present a new expressive model to describe requests abstractly using a “plan” represented by a directed graph. Our algorithmic result is an online algorithm for path computation and function placement that guarantees, in each time step, throughput of at least a logarithmic fraction of a (very permissive) upper bound on the maximal possible benefit.


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Copyright information

© Springer International Publishing AG 2016

Authors and Affiliations

  1. 1.School of Electrical EngineeringTel Aviv UniversityTel AvivIsrael
  2. 2.MPI for InformaticsSaarbrückenGermany

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