Patent ID: 7644182

Claim:
A method of detecting a degradation of quality of service in a multicast tree in an application layer multicast network, the method comprising: detecting at a child node in the multicast tree a degradation of quality of service associated with a service being received at the child node; determining whether the degradation of quality of service is resulting from a child-parent link or an upstream link to the child-parent link in the multicast tree, wherein the determining includes transmitting a complaint to a parent node of the child node, the complaint indicating a degradation of quality of service at the child node, if the parent node does not perceive the degradation of quality of service, a request is sent to a global information table for candidate parent nodes for the child node, and the request includes location information for the child node, if the parent node perceives the degradation of quality of service, the parent node sends a complaint to the parent node's parent node to determine if the parent node's parent node also perceives the degradation of quality of service, and the complaint includes location information for the parent node; selecting a new parent node for the child node from the candidate parent nodes in response to detecting the degradation of quality of service is resulting from the child-parent link; and selecting a new parent node for a child node incident to the upstream link in response to detecting the degradation of quality of service is resulting from the upstream link.