Patent ID: 8824293

Claim:
A method of implementing a packet processing unit in a switch device in communication with an upstream interface that is oversubscribed on ingress, the method comprising: in the packet processing unit: receiving multiple packets; utilizing at least one map to identify Quality of Service (QoS) information for each of the multiple packets, wherein utilizing the at least one map to identify QoS information includes: for a given packet of the multiple packets: selecting a QoS priority level amongst multiple different QoS priority levels; and prior to forwarding, modifying a header in the given packet to include the selected QoS priority level; based on the QoS information, select respective queues in which to forward the multiple packets to the upstream interface; and forwarding the multiple packets to the selected respective queues; wherein said at least one map contains port QoS levels and information on whether the port is trusted at L2 and L3 traffic layers.