WCF六种消息交换模式

https://docs.microsoft.com/zh-cn/dotnet/framework/wcf/extending/choosing-a-message-exchange-pattern

这使您总共有六种 MEP (Message Exchange Pattern)可以选择：

• 数据报 Datagram
• 请求-响应 Request-response
• 双工 Duplex
• 带会话的数据报 Datagram with sessions
• 带会话的请求-响应 Request-response with sessions
• 带会话的双工  Duplex with sessions
  

Web Services Message Exchange Patterns
https://www.w3.org/2002/ws/cg/2/07/meps.html