Two schemes for network QoS degradation locating

Future IP networks need to carry multimedia services with diverse quality of service (QoS) requirements. To sustain the contracted QoS needs not only to commit network resources, but also to monitor and control QoS adaptively. Locating the network segment that affects QoS negatively is crucial for controlling resources. The paper analyzes the current QoS distributed monitoring scheme and defines a new concept of key network segment (KNS). Two schemes, namely centralized locating scheme and distributed locating scheme, that can be used to locate KNS are proposed, analyzed, and compared. After KNS has been located, resources could be tuned to guarantee the contracted QoS.