Packet Buffer Sample Clauses

Packet Buffer. The DSPktBufBasic class enqueues and dequeues packets from or into one of 3 FIFO queues (for the 3 traffic classes), and implements the RED algorithm for buffer management (each queue is configured separately). It queues packets passed from the second stage DSMeterNTBs, and dequeues packets whenever the scheduling algorithm requests so (refer to Figure 9). In case the class is configured to be token-aware (this scheme was described in section 5.4), it checks whether a bit in the packet header is set to indicate that this packet was upgraded. If the packet was upgraded as determined by the DSMeterNTBs, it then creates a token packet (a placeholder in the queue) and inserts it in the upgrade class but inserts the physical packet in its original class (to preserve ordering). When the scheduler requests to dequeue a certain queue and a token packet is found, the lower class is dequeued instead, and the dequeued packet is upgraded (the indication bit is set in that packet). This implementation keeps the scheduler unaware of the token implementation (easier to change the scheduler). Note that the token awareness is turned off for the reordering SLA and the DiffServ models.