Which communication protocol and serialization method is supported?

Dear FedML Team,

I am currently writing a survey paper on Federated Computing. One part of it describes existing FL frameworks. Could you please let me know which communication protocol (e.g., gRPC, WebSocket, HTTP, GLOO) and serialization method (e.g., Pickle, JSON, Protobuf, FOBS) you supports I already saw in your documentation that you support gRPC, but maybe there is more.

Any help is highly appreciated.