在当今多媒体业务日趋增多 ,网络流量不断增加的情况下 ,基于数据报文传输模式的IP网络对于“服务质量” ,只能尽“最大努力” ,而TCP只是通过端到端的传输控制功能试图替代和减少网络自身的质量控制 ,显然这些难以保证足够的吞吐量和满足传送延迟等服务质量要求。从本质上说 ,流量工程是一种网络控制技术 ,其中包括接入控制、策略控制、质量控制和拥塞控制等。MPLS流量控制的目的就是解决尽力而为的传统IP服务与QoS的统一问题。在提出流量工程和MPLS流量工程的基本概念后 ,具体介绍了支持流量工程的 2种协议 :资源预约协议和基于强制路由的标签分配协议 ,并加以分析和比较。 In today’s increasingly multi-media business and increasing network traffic, IP networks based on data packet transmission can only do “best effort” for “quality of service,” while TCP attempts to replace it with end-to-end transmission control functions And reduce the network’s own quality control, it is clear that these are difficult to ensure adequate throughput and meet the quality of service requirements such as delivery delay. In essence, traffic engineering is a kind of network control technology, including access control, policy control, quality control and congestion control. The purpose of MPLS traffic control is to solve the unification problem of best effort traditional IP service and QoS. After the basic concepts of traffic engineering and MPLS traffic engineering are proposed, two kinds of protocols that support traffic engineering are specifically introduced: resource reservation protocol and label distribution protocol based on compulsory routing, and analyzed and compared.