Patent ID: 7047284

Claim:
A method for scheduling service requests from a plurality of nodes, each capable of generating a service request, said method comprising the steps of: disposing the plurality of nodes in a chain having an upstream most node and a downstream most node, said downstream most node connected to an application device capable of servicing the service requests; sequentially passing a token among the plurality of nodes from the upstream most node to the downstream most node following the chain, said token passing from the downstream most node to the upstream most node in a loop; determining at each node whether a service request is received from a next upstream node; determining at each node whether that node generates a service request; determining at each node whether that node holds the token; passing a service request received at one of the plurality of nodes from a next upstream node to a next downstream node if that node does not generate a service request, the downstream most node passing the service request to the application device; generating at the application device a service request acknowledgment upon receipt and acceptance of a service request by the application device, the service request acknowledgment indicating the node generating the accepted service request; passing a service request received at one of the plurality of nodes from the next upstream node to the next downstream node if that node generates a service request and that node does not hold the token; passing a service request generated by a node to the next downstream node if that node generates a service request and does not receive a service request from the next upstream node; passing a service request generated by a node to the next downstream node if that node generates a service request and that node holds the token; passing a service request acknowledgment received at one of the plurality of nodes from a next downstream node to said next upstream node, said downstream most node receiving said service request acknowledgment from the application device and said upstream most node discarding a received service request acknowledgment.