But DiffServ can not offer end-to-end QoS by itself,because it controls per-hop packet forwarding order with relative priority according toits class and does not consider the routing.

• 同时,DiffServ 自身只能根据业务流的相对优先级来控制数据分组在每一跳的转发顺序,而不考虑整个路由过程,不能提供端到端的QoS 保证。