US 2003/0189901 A1 · Upstream resource management propagation system and method for use in bufferless networks

Abstract

An Upstream Resource Management Propagation (“URMP”) solution is described that advantageously provides an algorithmic technique for reducing congestion in a bufferless network, such as an OBS network, through use of a scalable backpressure method. In one embodiment, the URMP algorithm is triggered by a congested node, causing URMP packets carrying congestion control information to be propagated from the congested node along the path destined for the ingress edge router(s) for a group of congested LSPs established according to GMPLS. The congestion control information includes the number of congested LSPs, the number of wavelengths involved, the maximum peak burst size, and a synchronization object to synchronize the clock time of the ingress edge routers. The congestion control information is used to instruct each ingress edge router as to when to transmit the burst packet for the corresponding LSP. During congestion, the transmission of flows is changed from asynchronous to time-division multiplex (“TDM”) with a rate-control mechanism.

Claims23

Dependent claims

A method of controlling congestion in a bufferless communications network comprising a plurality of interconnected nodes, the method comprising the steps of:

maintaining at each node congestion state information including congestion state data for each of a plurality of communications paths from an ingress edge router of the network to an egress edge router of the network that traverses the node;
and
upon detection of a current congestion at a congested node:
determining a current congestion set comprising all communications paths identified as participating in the current congestion;
updating congestion state information at the congested node;
and
sending congestion control information upstream to an ingress edge router identified as participating in the current congestion.

4 more elements

Apparatus for controlling congestion in a bufferless communications network comprising a plurality of interconnected nodes, the apparatus comprising:

means for maintaining at each node congestion state information including congestion state data for each of a plurality of communications paths from an ingress edge router of the network to an egress edge router of the network that traverses the node;
and
means for determining a current congestion set comprising all communications paths identified as participating in the current congestion, updating congestion state information at the congested node, and sending congestion control information upstream to an ingress edge router identified as participating in the current congestion upon detection of a current congestion at a congested node.

System for controlling congestion in a fiber optic network comprising a plurality of interconnected nodes, the system comprising:

congestion state information at each node including congestion state data for each of a plurality of Label Switched Path (“LSP”) from an ingress edge router of the network to an egress edge router of the network that traverses the node;
wherein upon detection of a current congestion at a congested node, the congested node determines a current congestion set comprising all LSPs identified as participating in the current congestion, updates congestion state information at the congested node;
and sends congestion control information upstream to an ingress edge router identified as participating in the current congestion;
and
wherein the upstream node uses the congestion control information to update the congestion state information at an upstream node along the LSP from the congested node to the ingress edge router.

2 more elements

Dependencies are inferred from the claim text.

Upstream resource management propagation system and method for use in bufferless networks

Life of this patent

Upstream resource management propagation system and method for use in bufferless networks

Life of this patent

Abstract

Claims23