Patent ID: 8385206

Claim:
A method of operating a traffic conditioner in a packet communications network, said traffic conditioner outputting a marked packet stream from an output of said traffic conditioner, said traffic conditioner including at least one token bucket having respective first and second token counts and respective first and second token parameter sizes, wherein said token counts are updated in accordance with at least one information rate, said method comprising the steps of: incrementing said first token count by one if said first token count is less than said first token parameter size; incrementing said second token count if said second token count is less than said second token parameter size, wherein if said first token count is greater than or equal to the first parameter size then the first token count is not incremented and if said second token count is greater than or equal to said second token parameter size, then said second token count is not incremented; and when a packet of size B bytes arrives at time t, the traffic conditioner operates in a color blind mode as follows: if the first token count at time t minus B is greater than zero, the packet is colored green and both the first token count and second token count are decremented by B down to a minimum value of zero, else; if the second token count at time t minus B is greater than zero, the packet is colored yellow and both the first token count and second token count are decremented by B down to a minimum value of zero, else; the packet is colored red and neither the first token count nor the second token count is decremented, and when a second packet of size B bytes arrives at time t, said traffic conditioner in a color aware mode in accordance with the following steps: if the second packet is pre-colored as green and the first token count at time t minus B is greater than zero, the second packet is colored green and both the first token count and second token count are decremented by B down to a minimum value of zero, else; if the second packet has been pre-colored as green or yellow and the second token count at time t minus B is greater than zero, the second packet is colored yellow and both the first token count and second token count are decremented by B down to a minimum value of zero, else; the second packet is colored red and neither the first token count nor the second token count is decremented.