@article{8795,
  abstract     = {{Softwarized networks are the key enabler for elastic, on-demand service deployments of virtualized network functions. They allow to dynamically steer traffic
through the network when new network functions are instantiated, or old ones
are terminated. These scenarios become in particular challenging when stateful functions are involved, necessitating state management solutions to migrate
state between the functions. The problem with existing solutions is that they typically embrace state migration and flow rerouting jointly, imposing a huge set
of requirements on the on-boarded virtualized network functions (VNFs), eg,
solution-specific state management interfaces.
To change this, we introduce the seamless handover protocol (SHarP). An
easy-to-use, loss-less, and order-preserving flow rerouting mechanism that is
not fixed to a single state management approach. Using SHarP, VNF vendors
are empowered to implement or use the state management solution of their
choice. SHarP supports these solutions with additional information when flows
are migrated. In this paper, we present SHarP's design, its open source prototype
implementation, and show how SHarP significantly reduces the buffer usage at
a central (SDN) controller, which is a typical bottleneck in state-of-the-art solutions. Our experiments show that SHarP uses a constant amount of controller
buffer, irrespective of the time taken to migrate the VNF state.}},
  author       = {{Peuster, Manuel and Küttner, Hannes and Karl, Holger}},
  issn         = {{1055-7148}},
  journal      = {{International Journal of Network Management}},
  title        = {{{A flow handover protocol to support state migration in softwarized networks}}},
  doi          = {{10.1002/nem.2067}},
  year         = {{2019}},
}