USP requires a mechanism to serialize data to be sent over a message transfer protocol. The description of each individual message and the USP Record encoding scheme is covered in a section of this document and/or in the referenced specification. This version of the specification includes support for:
R-ENC.0 - An implementation using protocol buffers encoding to encode USP Messages (Requests, Responses, and Errors) MUST conform to the schema defined in usp-msg.proto.
R-ENC.1 - An implementation using protocol buffers encoding to encode USP Records MUST conform to the schema defined in usp-record.proto.
Protocol Buffers Version 3 uses a set of enumerated elements to coordinate encoding and decoding during transmission. It is intended that these remain backwards compatible, but new versions of the schema may contain new enumerated elements.
R-ENC.2 - If an Endpoint receives a USP payload containing an unknown enumeration value for a known field, the Endpoint MUST report the failure to the receiving MTP to indicate a “bad request” and do no further processing of the USP Record or USP Message.
<– Message Transfer Protocols
End-to-End Messages Exchange –>