why Fast-CDR but not protobuf?

[chengfang0911]

why Fast-DDS use Fast-CDR to serialization but not protobuf?

[JLBuenoLopez]

Fast DDS is an implementation of the OMG DDS specification. The DDS Interoperability Wire Protocol is defined in the DDSI-RTPS specification. This specification defines the Common Data Representation (CDR) to be used for DDS interoperability. Fast CDR is an implementation of Section 10 of the specification. Consequently, protobuf is not used because the specification states that CDR must be used in order to be interoperable with other DDS implementations. Nevertheless, you can prepare your own TypeSupport so you can use Fast DDS with protobuf serialization.

[chengfang0911]

thanks