Huawei Huawei Ciena Service Function Chaining (SFC) provides a flexible way to construct services. When applying a particular service function chain to the traffic, the traffic needs to be steered through an ordered set of service functions in the network. This ordered set of service functions in the network, referred to as a Service Function Path (SFP), is an instantiation of the service function chain in the network. Segment Routing (SR) technique can be leveraged to steer the traffic through the SFP in SR networks. This document describes a PCE-based SFC architecture in which the PCE is used to compute a service function path (i.e., instantiate a service function chain) in SR networks.