Method for efficient aggregation of link metrics

A method for providing efficient aggregation of link metrics, including bandwidth and delay, for a subnetwork in a communication network having a plurality of interconnected subnetworks that consist of nodes and links, comprising the steps of:

• A) selecting a subset of the nodes in a subnetwork of the communication network to be exposed nodes,
• B) mapping the original subnetwork topology to a full-mesh virtual topology such that each virtual link connecting a pair of exposed nodes on the full-mesh virtual topology is derived utilizing at least one of:
• B1) determining a maximum bandwidth path connecting each pair of exposed nodes in the original subnetwork topology and representing each maximum bandwidth path by a virtual link whose link metric values equal respective metric values of the maximum bandwidth path and wherein a collection of all virtual links constitutes the full-mesh virtual topology,
• B2) determining a minimum delay path connecting each pair of exposed nodes in the original subnetwork topology and representing each minimum delay path by a virtual link whose link metric values equal respective metric values of the minimum delay path and wherein a collection of all virtual links constitutes the full-mesh topology;
• C) where the full-mesh virtual topology is determined with the maximum bandwidth objective, further utilizing the steps of:
• C1) determining an encoding for bandwidth metrics associated with the full mesh virtual topology, and advertising encoded bandwidth metrics by means of:
• C1a) determining, from the full-mesh virtual topology, a Maximum Bandwidth Spanning Tree using a Maximum Spanning Tree algorithm and bandwidth as link weights, and
• C1b) distributing the bandwidth of the virtual links in the Maximum Bandwidth Spanning Tree to nodes outside the subnetwork;
• and
• C2) determining an encoding for delay metrics associated with the full-mesh virtual topology, and advertising encoded delay metrics by means of:
• C2a) determining, from the full-mesh topology, a Maximum Delay Spanning Tree using a Maximum Spanning Tree algorithm and delay as link weights, and
• C2b) distributing the delay of the virtual links in the Maximum Delay Spanning Tree to nodes outside the subnetwork;
• D) where the full-mesh virtual topology is determined with the minimum delay objective, further utilizing the steps of:
• D1) determining an encoding for the bandwidth metrics associated with the full-mesh virtual topology, and advertising encoded bandwidth metrics by means of:
• D1a) determining, from the full-mesh virtual topology, a Minimum Bandwidth Spanning Tree using a Minimum Spanning Tree algorithm and bandwidth as link weights, and
• D1b) distributing the bandwidths of the virtual links in the Minimum Bandwidth Spanning Tree to nodes outside the network;
• and
• D2) determining an encoding for delay metrics associated with the full-mesh virtual topology, and advertising encoded delay metrics by means of:
• D2a) determining, from the full-mesh virtual topology, a Maximum Delay Spanning Tree using a Maximum Spanning Tree algorithm and delay as link weights, and
• D2b) distributing the delay of the virtual links in the Maximum Delay Spanning Tree to nodes outside the subnetwork.