| 1. | In tranditional ip network , only the “ best effort ” service is provided , but the quality of service can not be guaranteed . though the interserv , deffserv and mpls are presented afterward to guarantee the qos for the ip network . but as a layer network , the realization of the qos function need span different layers ( such as rsvp protocol ) in the ip network , which may result in the function iterance and chaos
多媒体和实时业务的出现要求网络能够提供足够的qos保证,在传统的ip网络中只能提供“尽量传输”的服务而不能保证服务质量,后来提出的综合服务模型( interserv )以及区分服务模型( deffserv )以及mpls技术保证了ip网络上的服务质量,但由于ip网络是层次结构的网络,因此对qos的支持需要跨层(如rsvp协议) ,这就可能引起功能的重复和混乱,而微通信元系统是无层次结构的网络系统,就克服了这些的问题,变得简单,效率更高。 |
