Packet priority in a network processor
View Patent ↗In a network processor, a “port-kind” identifier (ID) is assigned to each port. Parsing circuitry employs the port-kind ID to select the configuration information associate with a received packet. The port kind ID can also be stored at a data structure presented to software, along with a larger port number (indicating an interface and/or channel). Based on the port kind ID and extracted information about the packet, a backpressure ID is calculated for the packet. The backpressure ID is implemented to assign a priority to the packet, as well as determine whether a traffic threshold is exceeded, thereby enabling a backpressure signal to limit packet traffic associated with the particular backpressure ID.
1. A method of processing packets comprising:
receiving, from a network interface, a packet and a port identifier (ID), the port ID indicating a channel associated with the packet, the channel being a subset of communications at the network interface;
comparing the port ID against entries in a table to determine instructions for processing the packet, the table storing a plurality of port IDs with corresponding instructions;
determining a backpressure ID based on the port ID and information regarding the packet;
incrementing a resource counter corresponding to the backpressure ID; and
in response to detecting the resource counter reaching a threshold, sending a control signal to the network interface to limit operation of the channel;
assigning a priority to the packet based on the backpressure ID.
2. The method of claim 1 , wherein the information regarding the packet includes packet data.
3. The method of claim 2 , wherein the packet data includes one or more of a Virtual Local Area Network (VLAN) tag, HiGig tag, Digital Signature Algorithm (DSA) tag, Differentiated Services (diffserv) tag, a packet instruction header, and a customer configured custom field from the packet.
4. The method of claim 1 , wherein the control signal is configured to cause a network element upstream from the network interface to limit packet transmission to the network interface.
5. An apparatus comprising:
an input port for receiving packets from a plurality of network interfaces, each of the packets having an associated port identifier (ID), the port ID indicating a channel associated with the packet, the channel being a subset of communications at the network interface;
a parsing circuit configured to 1) compare the port ID against entries in a table to determine instructions for processing the packet, the table storing a plurality of port IDs with corresponding instructions, 2) determine a backpressure ID based on the port ID and information regarding the packet, and 3) assigns a priority to the packet based on the backpressure ID; and
a backpressure control circuit configured to increment a resource counter corresponding to the backpressure ID and, in response to detecting the resource counter reaching a threshold, send a control signal to the respective network interface to limit operation of the channel.
6. The apparatus of claim 5 , wherein the information regarding the packet includes packet data.
7. The apparatus of claim 6 , wherein the packet data includes one or more of a Virtual Local Area Network (VLAN) tag, HiGig tag, Digital Signature Algorithm (DSA) tag, Differentiated Services (diffserv) tag, a packet instruction header, and a customer configured custom field from the packet.
8. The apparatus of claim 5 , wherein the control signal is configured to cause a network element upstream from the network interface to limit packet transmission to the network interface.