Pseudo wire processing in a packet forwarding device
A method is provided for pseudo wire processing in a packet forwarding device in which a packet is processed based on whether the ports through which the packet is transmitted are real or pseudo wire ports. The inbound and outbound port information is encoded using a predefined range of index values such that index values falling within one range of values are used for passing real port information, and index values falling within another range of values are used for passing pseudo wire port information. The index values are used in a manner that facilitates efficient performance of pseudowire processing for the packets in the switch fabric component of the packet forwarding device.
1. An article of manufacture for pseudowire processing in a packet forwarding device comprising:
a non-transitory computer-readable medium including instructions that, when executed on a computer processor, cause the processor to:
determine whether an inbound port through which a packet has been transmitted to a packet forwarding device is a real port or a pseudowire port, wherein determining is performed in conjunction with inbound port information stored in at least one of a forwarding data base and an inbound label map of the packet forwarding device;
encode the inbound port through which the packet is transmitted in a value of a first index having a predefined range of values representing real ports and pseudowire ports, the value based on whether the inbound port is determined to be the real port or the pseudowire port in conjunction with the stored inbound port information;
encode an outbound port through which the packet will be transmitted in a value of a second index having a predefined range of values representing real ports and pseudowire ports; and
perform outbound packet processing for the packet in a switch fabric of the packet forwarding device based on determining, within their respective predefined range of values, where the first index value and the second index value fall, including:
determining whether the packet is transmitted through the packet forwarding device homogeneously, wherein the respective predefined ranges within which the first and second index values fall both represent real ports or both represent pseudowire ports, or heterogeneously, wherein the respective predefined ranges within which the first and second index values fall represent different types of ports, one representing a real port and the other representing a pseudowire port;
performing echo kill processing for packets transmitted homogenously; and
bypassing echo kill processing for packets transmitted heterogeneously.
2. The article of manufacture of claim 1 , wherein the non-transitory computer-readable medium further includes instructions that cause the processor to perform multicast processing based on the value of the second index having the range of values representing real ports and pseudowire ports that indicates whether the packet requires multicast processing or unicast processing, wherein multicast processing includes instructions to:
access a list of multicast entries corresponding to the value of the second index, the multicast entries being accessed via a multicast pointer and a copy counter; and
generate, for each entry in the list of multicast entries corresponding to the value of the second index, a new value for the second index; and
further perform outbound packet processing for the packet in the switch fabric of the packet forwarding device based on the new value of the second index, the new value of the second index falling within the predefined range of values for the second index representing real ports and pseudowire ports.
3. The article of manufacture of claim 1 , wherein the non-transitory computer-readable medium further includes instructions that cause the processor to:
map the value of the second index to a value of a third index, wherein values of the third index correspond to outbound port entries stored on the packet forwarding device, the entries for obtaining outbound port numbers;
access the outbound port entry to which the value of the third index corresponds; and
obtain an outbound port number to be used when transmitting the packet to an outbound port based on the outbound port entry to which the value of the third index corresponds.
4. A computer-implemented method for pseudowire processing in a packet forwarding device, the method comprising:
determining whether an inbound port over which a packet is being received is real or pseudowire based on inbound port information stored in the packet forwarding device;
encoding the inbound port in a value of an abstract port tag index having a predefined range of values representing real ports and pseudowire ports, the abstract port tag index value indicating whether the inbound port is real or pseudowire;
determining whether a tentative outbound port over which the packet is to be transmitted is real or pseudowire based on outbound port information stored in the packet forwarding device;
encoding the tentative outbound port in a value of an egress port tag index having a predefined range of values representing real ports and pseudowire ports, the egress port tag index value indicating whether the tentative outbound port is real or pseudowire; and
performing pseudowire processing for the packet in a switch fabric of the packet forwarding device based on where the abstract port tag index and the egress port tag index values fall within their respective predefined range of values, including mapping the egress port tag index value to an actual outbound port, the actual outbound port being real or pseudowire.