A circuit operates to manage transmittal of packets in a network packet processor. The circuit includes a packet descriptor manager (PDM), a packet scheduling engine (PSE), and a packet engines and buffering module (PEB). The PDM generates a metapacket and a descriptor from a command signal, where the command signal identifies a packet to be transmitted by the circuit. The PSE determines an order in which to transmit the packet among a number of packets, where the PSE determines the order based on information indicated in the metapacket. Once the packet is scheduled for transmission, the PEB performs processing operations on the packet to produce a processed packet based on instructions indicated in the descriptor. The PEB then causes the processed packet to be transmitted toward the destination.