本文件规定了统一诊断服务（ISO？14229-1）与所有传输协议和网络层服务（例如ISO？13400-2 DoIP、ISO？15765-2 DoCAN、FlexRay上的ISO？10681-2通信、ISO？14230-2 DoK线路和ISO？20794-3 CXPI）之间的独立性的通用会话层服务和要求。 本文件规定了OSI第5层（会话）和第4层（传输）之间通过所谓的服务请求/指示/确认原语的公共服务原语接口。

This document specifies common session layer services and requirements to provide independence between unified diagnostic services (ISO？14229-1) and all transport protocols and network layer services (e.g. ISO？13400-2 DoIP, ISO？15765-2 DoCAN, ISO？10681-2 communication on FlexRay, ISO？14230-2 DoK-Line, and ISO？20794-3 CXPI). This document specifies a common service primitive interface between OSI layer 5 (session) and layer？4 (transport) via so-called service request/indication/confirmation primitives.