The Design and Specification of Path Adjustable SFC Using YANG Data Model

The service requirements from the customer are getting more and more complicated, and the users' demands for continuous uptime availability guaranteed in SLA become more and more strict. Under such circumstances, Service Function Chaining (SFC) requires more flexibility and scalability. Therefore researchers and developers have proposed plenty of complex structured solutions for the provisioning of SFC in the network. In this paper, to specify and configure these complex structured SFC, the concept of Path Adjustable SFC (P A-SFC) is proposed. After analyzing its possible traffic steering, two forwarding modes - load balancing mode and parallel mode are designed. Then the PA-SFC is modeled using YANG data modeling language. With the proposed approach, the SFC can be adjusted into a parallel chain or multiple loads balancing chains automatically under the control of the SDN controller.