Message Exchange Patterns (MEPs)
- <operation>
specifies message types and desired MEP
- MEP
defines a pattern of interaction between agents
- WSDL 2.0 defines base set of MEPs:
- In-Out, In-Only, Out-In, Out-Only
- Robust-In-Only, Robust-Out-Only (permit optional fault)
- Out-Optional-In, In-Optional-Out (reply is optional)
- Each MEP is identified by a URI
- Extensible: Other MEPs can also be used (identified by URI)