基于IP实时通信的实时出版—定购协议

Real-Time Publish-Subscribe Protocol for IP-Based Real-Time Communicatio

IP,TCP,UDP是因特网通信的标准传输协议 ,但这些协议对于应用程序开发过于底层。用来做商业应用的高层协议 ,比如 HTTP,CORBA和 DCOM已经被开发出来 ,但是 ,许多分布实时应用程序的开发者发现他们没有提供恰当的抽象层次或关键功能。例如没有一个协议能为起决定作用的通信、对时间有感知的通告、主控制者状态通告、透明的热交换替代或服务质量控制提供支持。用标准因特网传输的出版—订购协议已经被开发出来 ,它支持分布式实时进程间通信。这个协议已被 IDA(Interface for Distributed Automation)采用。本文描述了设计要求 ,并介绍了怎样用标准 U DP/ IP在有严格时间期限要求的应用程序中实现网络质量决定传输质量、可靠的出版—订购和客户—服务器模型的消息机制。

IP,TCP and UDP are the standard Internet transport protocols.These protocols,however,are too lowlevel for application development.Higherlevel protocols such as HTTP,CORBA,and DCOM have been developed for commercial applicaions.However,they do not provide the right level of abstraction or key functionality.For example,none offer help for deterministic communications,timeaware notifications,heartbeats,transparent hotswap substitution,or quality of service controls.A publishsubscribe protocol has been developed that uses the standard Internet transports and offers support for distributed realtime interprocess communications.This protocol has been adopted by the IDA group.This paper describes the design requirements and shows how the standard UDP/IP protocol can be used for besteffort and reliable publishsubscribe and clientserver messaging in applications with rigorous deadline requirements.