Resource allocation methods and apparatus

A communications system comprising:

• a first session border controller comprising:
• a processor;
• and
• memory;
• wherein said processor is configured to:
• operate a first resource manager, of the first session border controller, as a master resource manager for a plurality of session border controllers in a cluster of session border controllers, said first session border controller being one of the plurality of session border controllers in said cluster, operating the first resource manager including:
• receiving, at the first resource manager, resource utilization reporting messages from session border controllers in said cluster, said resource utilization reporting messages including resource utilization information;
• determining, at the first resource manager, from the reported resource utilization information which of a plurality of session border controller modes of operation the session border controllers are to operate in for a first resource group, said plurality of modes of session border controller operation for the first resource group including at least:
• i) a normal mode of operation in which session border controllers in the cluster report resource utilization for the first resource group to the first resource manager at fixed time interval spacing T and ii) a critical mode of operation in which session border controllers in said cluster communicate resource utilization reporting messages for the first resource group to said first resource manager at a faster rate than during said normal mode of operation and during which the session border controllers reject any resource allocation requests requesting resources in the first resource group that would require a resource allocation exceeding an allocation limit assigned to an individual session border controller performing a resource allocation;
• wherein said normal mode of operation is determined when the reported resource utilization for the first resource group is below or equal to a first threshold and said critical mode of operation is determined when the reported resource utilization for the first resource group is above the first threshold;
• wherein during said normal mode of operation a session border controller can allocate resources above a resource allocation limit specified for the first resource group by the first resource manager for the individual session border controller performing the resource allocation;
• and
• communicating the determined mode of operation for the first resource group to one or more session border controllers in said cluster.

A non-transitory machine readable medium including processor executable instructions, which when executed by a processor of a first session border controller control the first session border controller to:

• operate a first resource manager, of the first session border controller, as a master resource manager for a plurality of session border controllers in a cluster of session border controllers, said first session border controller being one of the plurality of session border controllers in said cluster, operating the first resource manager including:
• receive, at the first resource manager, resource utilization reporting messages from session border controllers in said cluster, said resource utilization reporting messages including resource utilization information;
• determine, at the first resource manager, from the reported resource utilization information which of a plurality of session border controller modes of operation the session border controllers are to operate in for a first resource group, said plurality of modes of session border controller operation for the first resource group including at least:
• i) a normal mode of operation in which session border controllers in the cluster report resource utilization for the first resource group to the first resource manager at fixed time interval spacing T and ii) a critical mode of operation in which session border controllers in said cluster communicate resource utilization reporting messages for the first resource group to said first resource manager at a faster rate than during said normal mode of operation and during which the session border controllers reject any resource allocation requests requesting resources in the first resource group that would require a resource allocation exceeding an allocation limit assigned to an individual session border controller performing a resource allocation;
• wherein said normal mode of operation is determined when the reported resource utilization for the first resource group is below or equal to a first threshold and said critical mode of operation is determined when the reported resource utilization for the first resource group is above the first threshold;
• wherein during said normal mode of operation a session border controller can allocate resources above a resource allocation limit specified for the first resource group by the first resource manager for the individual session border controller performing the resource allocation;
• and
• communicate the determined mode of operation for the first resource group to one or more session border controllers in said cluster.