Patent ID: 7660251

Claim:
An apparatus for implementing hierarchical scheduling of virtual paths with underutilized bandwidth comprising: a scheduler including a first calendar for pipes and autonomous flows; said scheduler including a secondary calendar for pipe flows; dequeue and reattach logic coupled to said first calendar and said secondary calendar; pipe queues logic coupled between said secondary calendar and said dequeue and reattach logic; said scheduler identifying a winner of a pipe or an autonomous flow from said first calendar; said dequeue and reattach logic responsive to an identified winner pipe, checking said pipe queue logic for an associated pipe flow for said winner pipe; and said dequeue and reattach logic responsive to identifying an empty pipe queue for said winner pipe, assigning a pipe win credit to said identified winner pipe without reattaching said identified winner pipe to said first calendar; and said scheduler identifying a next winner of a pipe or an autonomous flow from said first calendar, responsive to said pipe win credit being assigned; said pipe queues logic, responsive to identifying a pipe flow winner from said secondary calendar, checking for said respective pipe win credit being assigned, and responsive to identifying said respective pipe win credit being assigned, notifying said dequeue and reattach logic and said pipe queues logic clearing said respective pipe win credit; said dequeue and reattach logic, responsive to being notified of said pipe flow winner and said respective pipe win credit being assigned, servicing said pipe flow winner substantially without delay; said dequeue and reattach logic transmitting data, reattaching said pipe to said first calendar, and reattaching said associated winner pipe flow to said secondary calendar.