| 1. Definition | 2. Functional Requirements | 3. Syntax | 4. Semantics |
1 Definition
An Item that a Source Process sends to a Destination Process requesting the performance of a Process Action.
2 Functional Requirements
An Inter-Process Protocol (IPP) Message may be a Process Action Request (PA Request) or Process Action Response (PA Response) composed of the following elements. Additional Details at Protocols.
| IPP Message Elements | Description |
| Time | Provided by communication infrastructure. |
| Message ID | ID of PA Request or PA Response. |
| Response ID | Absent/Present when the Message is a PA Request/PA Response. |
| Source Process ID | ID of Process issuing Message. |
| Process Action | Combination of Action, Items/Processes and Complement (see Process Action). |
| Resolution Service ID | Service that: 1. Receives a Message from a Process in its M-Instance and forwarding it to a peer Process in a different M-Instance, or 2. Sends a Message received from a peer Process in a different M-Instance to a Process in its M-Instance. (Absent if the two Processes are in the same M-Instance). |
| Destination Process ID | ID of Process to which the Message is intended to be sent. |
| Message Status | Ack, if successful, if failure, Error as follows: 1. “Unable” to perform request. 2. “ValueRQ” Transaction of Value required. 3. “ConvFail” Conversion Service failure. |
3 Syntax
https://schemas.mpai.community/MMM4/V2.1/data/IPPMessage.json
4 Semantics
| Label | Description |
| Header | IPP Message Header |
| – Standard-IPPMessage | The characters “MMM-IPM-V” |
| – Version | Major version – 1 or 2 characters |
| – Dot-separator | The character “.” |
| – Subversion | Minor version – 1 or 2 characters |
| IPPMessageID | Identifier of Message. |
| IPPMessage | Number of Bytes in Message Data |
| – ResponseID | As specified in Inter-Process Protocol. |
| – SourceProcessID | As specified in Inter-Process Protocol. |
| – ProcessAction | As specified in Inter-Process Protocol. |
| – ResolutionServiceID | As specified in Inter-Process Protocol. |
| – DestinationProcessID | As specified in Inter-Process Protocol. |
| – Acknowledgement | As specified in Inter-Process Protocol. |
| DescrMetadata | Descriptive Metadata. |
