Distributed connection admission-control

A communications network node connected by links to at least one other node of a communications network, the communications network node comprising:

• a dynamic load distributor for distributing at least one traffic flow from a respective ingress node to a respective egress node via at least one respective path in a communications network, each of said at least one traffic flow having at least one associated minimum service level requirement, said dynamic load distributor comprising
• a calculator for determining path weights for paths available for traffic flows sent to said communications network node;
• a flow distributor for distributing said traffic flows from said communications network node to at least one neighboring node via respective links based on said path weights and dynamic link costs associated with said respective links;
• and
• a signaler for sending at least one traffic source node a back-off signal requesting said at least one traffic source node to send less traffic to said communications network node, if said communications network node becomes so congested that said communications network node fails to distribute the at least one traffic flow according to the at least one associated minimum service level requirement;
• and
• a connection admission controller for receiving a request to admit a new traffic flow to said communications network, for admitting said request, if said communications network node has not received the back-off signal from another node of said communications network, for redistributing the at least one traffic flow to at least one alternative path, if said communications network node has received the back-off signal from the another node of said communications network, for admitting said request, if said redistribution succeeds, and for rejecting said request, if said redistribution fails due to unavailable alternative paths.

A communications network node connected by links to at least one other node of a communications network, the communications network node comprising:

• a dynamic load distributing means for distributing at least one traffic flow from a respective ingress node to a respective egress node via at least one respective path in a communications network, each of said at least one traffic flow having at least one associated minimum service level requirement, said dynamic load distributing means comprising
• a calculating means for determining path weights for paths available for traffic flows sent to said communications network node;
• a flow distributing means for distributing said traffic flows from said communications network node to at least one neighboring node via respective links based said path weights and dynamic link costs associated with said respective links;
• and
• a signaling means for sending at least one traffic source node a back-off signal requesting said at least one traffic source node to send less traffic to said communications network node, if said communications network node becomes so congested that said communications network node fails to distribute the at least one traffic flow according to the at least one associated minimum service level requirement;
• and
• a connection admission controlling means for receiving a request to admit a new traffic flow to said communications network, for admitting said request, if said communications network node has not received the back-off signal from another node of said communications network, for redistributing the at least one traffic flow to at least one alternative path, if said communications network node has received the back-off signal from the another node of said communications network, for admitting said request, if said redistribution succeeds, and for rejecting said request, if said redistribution fails due to unavailable alternative paths.

A computer program, embodied on a computer readable medium, for distributed connection admission control for a communications network comprising nodes connected by links, the computer program controlling a data-processing device to perform the steps of:

• distributing at least one traffic flow from a respective ingress node to a respective egress node via at least one respective path in a communications network, each of said at least one traffic flow having at least one associated minimum service level requirement, said distributing performed locally at at least one node and including
• determining, at a given node, path weights for paths available for traffic flows sent to said given node,
• distributing said traffic flows from said given node to at least one neighboring node via respective links based on said path weights and dynamic link costs associated with said respective links, and
• sending at least one traffic source node a back-off signal requesting said at least one traffic source node to send less traffic to said given node, if said given node becomes so congested that said given node fails to distribute the at least one traffic flow according to the at least one associated minimum service level requirement;
• receiving, at an access node, a request to admit a new traffic flow to said communications network;
• admitting said request, if an access node has not received the back-off signal;
• redistributing the at least one traffic flow at said access node to at least one alternative path, if said access node has received the back-off signal;
• admitting said request, if said redistribution at said access node succeeds;
• and
• rejecting said request, if said redistribution at said access node fails due to unavailable alternative paths.