# US 7,609,626 B2 · Nodes for managing congestion and traffic flow by considering the minimization of link utilization values > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,626 B2 - Document ID: US7609626B2 - Status: Granted - Kind: B2 - Application number: 11/454,833 - Filed: 2006-06-19 - Published: 2007-04-05 - Granted: 2009-10-27 - Earliest claimed: 2004-04-16 - Assignees: Alcatel-Lucent USA Inc. - Inventors: Yufei Wang; Zheng Wang; Leah Zhang - Web page: https://patentgrep.com/patent/US7609626B2 ## CPC - H04L 43/0882: Utilisation of link capacity - H04L 41/083: for increasing network speed - H04L 41/5025: by proactively reacting to service quality change, e.g. by reconfiguration after service quality degradation or upgrade - H04L 45/00: Routing or path finding of packets in data switching networks (routing or path finding in wireless networks H04W40/00) - H04L 45/12: Shortest path evaluation - H04L 45/123: {Evaluation of link metrics (techniques for monitoring network metrics H04L43/08)} - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 41/5003: Managing SLA; Interaction between SLA and QoS - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Traffic demands are routed across links of an information network so as to avoid congestion and allow for future traffic growth. Traffic demands from a source node to a destination node of the network are monitored, including bandwidths associated with each of the demands. For each demand, and for a given link of the network, that portion of the bandwidth associated with each traffic demand which is provided by the given link, is determined. A maximum value of link utilization among all links of the network is then determined, wherein link utilization is defined as the amount of bandwidth used by all traffic demands routed through a given link with respect to a total capacity of the link. Traffic demands are then routed across the links of the network in such a manner as to minimize the maximum value of link utilization. ## Claims ### Claim 1 A traffic management system operable to route traffic along a path by: monitoring traffic demands from a source node of an information network to a destination node of the network, including bandwidths associated with each of the traffic demands; determining for each traffic demand and for a given link of the network, that portion of the bandwidth associated with each traffic demand which portion is provided by the given link; determining a maximum value of link utilization among all links of the network, where link utilization is defined as the amount of bandwidth used by all traffic demands routed through a given link with respect to a total capacity of the link; calculating a cost metric for each link of the network based on information comprising the traffic demand and maximum value of link utilization; selecting a path with consideration to minimizing the maximum value of link utilization based on each cost metric; and routing the traffic demands across the path. ### Claim 2 (depends on 1) The traffic management system as in claim 1 further operable to route traffic demands over more than one path in the network. ### Claim 3 (depends on 1) The traffic management system as in claim 1 further operable to route each traffic demand over a single path in the network. ### Claim 4 A traffic management system operable to route traffic along a path by: receiving a demand to route network traffic; determining a demand size of the demand; determining a routing procedure associated with the demand; calculating a cost metric for each of a plurality of links of a network, the cost metric for each link being associated with information comprising the routing procedure and a link utilization, the link utilization being a ratio of link capacities; and selecting a path with consideration to minimizing a maximum utilization value of link utilization to route network traffic based on the calculated cost metric for each of the plurality of links. ### Claim 5 (depends on 4) The traffic management system as in claim 4 further operable to route traffic over a multi-protocol label switching network. ### Claim 6 (depends on 4) The traffic management system as in claim 4 wherein the cost metric is determined by a ratio of the used link capacity and the demand size to the total link capacity. ### Claim 7 (depends on 4) The traffic management system as in claim 4 wherein the cost metric is associated with a percentage of link idle capacity. ### Claim 8 (depends on 4) The traffic management system as in claim 4 further operable to chose the path with minimums hops or the shortest distance if there are multiple candidate paths. ### Claim 9 (depends on 4) The traffic management system as in claim 4 wherein the cost metric is associated with a maximum link utilization of the link, the demand size, and link utilization of the plurality of links. ### Claim 10 (depends on 4) The traffic management system as in claim 4 further operable to adjust the cost metric by a small scalar value and the demand size where a cost metric for a link is the same as a cost metric for another link. ### Claim 11 (depends on 4) The traffic management system as in claim 4 wherein the cost metric is associated with the link utilization, the demand size, a maximum link utilization for the link, a number of hops of a minimum hop path for the demand, and the link utilization of the plurality of links. ### Claim 12 (depends on 11) The traffic management system as in claim 11 further operable to select a shortest path as the selected path to route network traffic. ### Claim 13 (depends on 4) The traffic management system as in claim 4 further operable to select the path based on a weight associated with a calculated cost metric for each of the plurality of links, each weight being manipulated in a open shortest path first network.