Providing oversubscription of pipeline bandwidth

摘要

A system for providing oversubscription of pipeline bandwidth comprises a steer module, an absorption buffer, an ingress packet processor (IPP), a memory management unit (MMU), and a main packet buffer. The steer module receives packets that include start of packet (SOP), middle of packet (MOP), and end of packet (EOP) cells, attaches a packet identifier to the cells, passes the MOP and EOP cells to the MMU, and stores the SOP cells and EOP metadata in the absorption buffer. The IPP processes the SOP cells and EOP metadata and passes the same to the MMU. The MMU stores the MOP, EOP, and processed SOP cells in the main packet buffer, combines, upon receiving the processed EOP metadata of each packet, the processed SOP cell, the MOP cells and the EOP cell of each packet to reconstruct each packet, and queues each reconstructed packet in an egress port queue.

主权项

1. A system for providing oversubscription of pipeline bandwidth, the system comprising:
a steer module configured to allocate packet identifiers for packets comprising cells received over ingress ports, each packet comprising a start of packet cell, at least one middle of packet cell, and an end of packet cell, to attach the packet identifier allocated for each respective packet to each cell of the respective packet, to pass middle of packet cells and end of packet cells to a memory management unit, and for a packet, to store the start of packet cell and end of packet metadata extracted from at least one of the cells of the packet in an absorption buffer; an ingress packet processor configured to, for the packet, retrieve the start of packet cell and the end of packet metadata from the absorption buffer, perform ingress packet processing on the start of packet cell and the end of packet metadata, and pass the processed start of packet cell and the end of packet metadata to the memory management unit; and the memory management unit configured to, for the packet, store the at least one middle of packet cell and the end of packet cell in a main packet buffer, allocate memory in the main packet buffer for the start of packet cell of the packet when the memory management unit receives a first middle of packet cell of the packet before the start of packet cell of the packet, store the processed start of packet cell in the main packet buffer, combine the processed start of packet cell, the at least one middle of packet cell, and the end of packet cell to reconstruct the packet based at least in part on the packet identifiers attached to the cells of the packet, queue the reconstructed packet in a queue associated with an egress port, account for storage of the processed start of packet cell of the packet, the at least one middle of packet cell of the packet, and the end of packet cell of the packet in the main packet buffer against a first partition of the main packet buffer, and account for storage of the reconstructed packet in the main packet buffer against a second partition of the main packet buffer, wherein the memory management unit reconstructs the packet upon receiving the end of packet metadata corresponding to the packet.