In order to offer different kinds of IP-based Services on the evolving IP networks,the Service Providers must offer the Service Level Agreement (SLA)to the customers to guarantee the Quality of Service(QoS).

• 为在迅速发展的IP网络上提供各种基于IP的差异性业务,业务提供商必须为客户提供业务等级协议(SLA)以对客户做出服务质量(QoS)的保证。