gRPC server in BBSim (Broad Band Sim)

For scalability test of VOLTHA, which needs multiple OLTs/ONUs connected to OpenOLT Adapter, BBSim (Broad Band Simulator) acts as if it were multiple OLTs/ONUs, and response to the gRPC call sent from OpenOLT Adapter.

We assume this consists of two parts and is implemented by Golang.

・gRPC server … responds to the message from OpenOLT Adapter. The number of connections between OpenOLT Adapter  and BBSim (i.e., the number of OLTs which BBSim simulates) should be configured by CLI.

・State machine (if necessary) … manages the status of each OLT (and ONUs in the future)