Differentiated services for a network processor

A method of marking an information element in a flow, comprising:

• indicating whether the information element in the flow conforms to a peak rate and a committed rate;
• determining whether the information element should be accepted or discarded;
• and
• marking the information element with one of a plurality of mark values.

A method of marking an information element, comprising:

• determining whether the information element conforms to a peak rate;
• if the information element does not conform to the peak rate, then marking the information element with a first mark value;
• if the information element conforms to the peak rate, then determining whether the information element conforms to a committed rate;
• if the information element does not conform to the committed rate, then marking the information element with a second mark value;
• and
• if the information element conforms to the committed rate, then marking the information element with a third mark value.

A method of marking an information element in a flow, comprising:

• determining whether average usage of a class to which the flow belongs is less than or equal to a maximum threshold;
• if the average usage is greater than the maximum threshold, then marking the information element with a first mark value;
• if the average usage is less than or equal to the maximum threshold, then determining whether the average usage is less than or equal to a minimum threshold;
• if the average usage is greater than the minimum threshold, then marking the information element with a second mark value;
• and
• if the average usage is less than or equal to the minimum threshold, then marking the information element with a third mark value.

A method for traffic metering, comprising:

• receiving an information element in a flow;
• determining a length of the information element;
• calculating a required time between information elements;
• and
• determining whether the information element is a first information element of the flow:
• if the information element is the first information element of the flow, then a debt is set to zero and a last conforming time (“LCT”) is set to an arrival time of the first information element;
• and
• if the information element is not the first information element of the flow, then calculating the “actual time” between arrival of two successive information elements and adjusting the required time between information elements to produce a “token bucket” that accounts for the debt incurred by a previous information element.

A storage congestion metering unit comprising:

• a first multiplexer to select a particular one of a plurality of average occupancy counts that corresponds to a class to which a flow of an information element belongs.
• a class characteristic storage unit stores multiple entries, each of the entries corresponds to a particular one of a plurality of classes and each of the entries includes a scheduling entry that allows for a balanced discarding of the information element, a minimum number of occupied information segment storage units before a drop probability is used to determine whether to discard the information element, a maximum number of occupied information segment storage units at which threshold point the information element is discarded, a value “G” that specifies how often to increment the drop probability and a value “I” that specifies how much each drop probability increment should be;
• a compare unit coupled to the first multiplexer, wherein the compare unit has as inputs the particular one of the plurality of average occupancy counts and the minimum and maximum number of occupied information segment storage units;
• and
• a second multiplexer coupled to the compare unit;
• wherein
• if the compare unit finds that the particular one of the plurality of average occupancy counts is greater than or equal to the maximum number of occupied information segment storage units, then the compare unit instructs the second multiplexer to indicate that the information element is to be discarded;
• if the compare unit finds that the particular one of the plurality of average occupancy counts is less than the minimum number of occupied information segment storage units, then the compare unit instructs the second multiplexer to indicate that the information element is to be accepted;
• and
• if the compare unit finds that the particular one of the plurality of average occupancy counts is less than the maximum number of occupied information segment storage units and greater than or equal to the minimum number of occupied information segment storage units, then the compare unit instructs the second multiplexer to indicate whether to accept or discard the information element based on drop scheduling and the drop probability.

A method for storage congestion metering, comprising:

• selecting a particular one of a plurality of average occupancy counts that corresponds to a class to which a flow of an information element belongs;
• determining a drop probability for the class using the particular one of the plurality of average occupancy counts, a minimum number of occupied information segment storage units before a drop probability is used to determine whether to discard the information element, a maximum number of occupied information segment storage units at which threshold point the information element is discarded, a value “G” that specifies how often to increment the drop probability, and a value “I” that specifies how much each drop probability increment should be;
• comparing the particular one of the plurality of average occupancy counts and the minimum and maximum number of occupied information segment storage units;
• if the particular one of the plurality of average occupancy counts is greater than or equal to the maximum number of occupied information segment storage units, then outputting a signal to indicate that the information element is to be discarded;
• if the particular one of the plurality of average occupancy counts is less than the minimum number of occupied information segment storage units, then outputting a signal to indicate that the information element is to be accepted;
• and
• if the particular one of the plurality of average occupancy counts is less than the maximum number of occupied information segment storage units and greater than or equal to the minimum number of occupied information segment storage units, then outputting a signal to either discard or accept the information element based on drop scheduling and the drop probability.