Method and apparatus for controlling fanout of a multicast tree

A system for controlling fanout at an ingress node of a dynamic multicast tree for a multicast session in a differentiated services network, comprising:

• a plurality of edge nodes in the differentiated services network a selected one of the edge nodes being the ingress node, each of the edge nodes including a respective resource management entity programed to formulate, send and receive signaling messages related to the management of resources required for the multicast tree;
• and
• the resource management entities of the edge nodes being further adapted to receive a service level specification (SLS) that specifies a level of service to be provided for the multicast session, and to store in a memory at least one variable respecting a maximum number of egress points that may be grafted to the ingress node for the multicast tree;
• and if the ingress node cannot accept a graft request from another edge node in the differentiated services network, the resource management entity of the other edge node is programmed to send a graft-redirect message to a downstream requesting node to provide the downstream requesting node with an address of at least one egress node already grafted to the multicast tree.

A resource management entity for an edge node in a differentiated services network adapted to support dynamic multicast groups, comprising:

• means for accepting a service level specification (SLS) that specifies a level of service for a multicast session and at least one variable for defining a maximum number of egress points that may be grafted to the edge router when the edge node serves as an ingress node of a multicast tree for a dynamic multicast session;
• means for storing the at least one variable in a memory;
• means for receiving a graft request message from another node in the differentiated services network, the graft request message requesting permission to graft as a new egress point to the ingress node;
• means for determining whether the graft can be using the at least one variable for defining a maximum number of egress points;
• means for informing the other node respecting whether the graft can be accepted;
• and
• means for sending a graft-redirect message to a downstream requesting node when it is determined that the graft cannot be accepted, the graft-redirect message containing an address of at least one node already grafted to the multicast tree.