SINGLE AND DUAL RATE THREE COLOR MARKER SYSTEMS

• US 20100195504A1
• Filed: 12/23/2009
• Published: 08/05/2010
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Woo, Thomas Y., Nandagopal, Thyagarajan
• Granted Patent: US 8,385,206 B2
• Time in Patent Office: Days
• US Class Current: 370/235.1
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/20 Traffic policing
• CPC Class Codes: H04L 47/215 using token-bucket
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• CPC Class Codes: H04L 47/31 by tagging of packets, e.g. using discard eligibility [DE] bits

Abstract

An advance is made over the prior art in accordance with the principles of the present invention that is directed to a new approach for a system and method of Single Rate Three Color Marker (srTCM) and Two Rate Three Color Marker (trTCM) methodology. The invention eliminates deficiencies present in existing standards that allow a user to defeat the traffic meter that is used to ensure bandwidth usage is within limits imposed by the provider. Adoption of these invention will ensure compliance with the goals of an ideal Single Rate Three Color Marker (srTCM) and Two Rate Three Color Marker (trTCM) scheme.

Claims

1. 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 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.

2. The method of claim 1, wherein said traffic conditioner operates in a color aware mode when a packet of size B bytes arrives at time t, in accordance with the following steps:

if the packet is pre-colored as green and 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 packet has been pie-colored as green or yellow and 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 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.

3. The method of claim 1, wherein said first and second token parameters correspond to first and second token buckets.

4. The method of claim 1 wherein said at least one information rate is a committed information rate.

5. The method of claim 4, further including a peak information rate, wherein said second token count is incremented in accordance with a peak information rate up to said second token parameter size.

6. The method of claim 5, wherein said first and second token parameters are initially full at time t equals zero and equal to peak bucket size (PBS) and a committed bucket size (CBS), respectively, wherein the first token count is incremented by one CIR times per second up to CBS and the second token count is incremented by one PIR times per second up to PBS.

7. The method of claim 3, wherein said first and second token buckets are correspond to token buckets C and E, respectively, each token bucket having a respective token count Tc and Te, wherein at time zero, the token count haves sizes Te(0)−

CBS and Te(0)=EBS and thereafter the token count Tc is incremented by one CIR times per second (up to CBS), and the token count Te is incremented by one EIR times per second (up to EBS), wherein in a Color-Aware mode the traffic conditioner when receiving a packet of size B operates as follows;

if the packet has been pre-colored as green and Tc(t)−

B>

=0, the packet is green and Tc is set to max(0, Tc(t) B);

else

if the packet has been pre-colored as green or yellow and if Tc(t)+Te(t)−

B>

=0, the packet is yellow and Te is set to max(0, Te(t)−

B) and Tc is set to max(0, min(Tc(t), Tc(t)−

B+Te(t)));

else

the packet is red and neither Tc nor Te is decremented.

8. The method of claim 7, wherein in a Color-Blind mode of operation, all incoming packets are treated as colored green.

9. A traffic conditioner apparatus 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 apparatus comprising:

means for incrementing said first token count by one if said first token count is less than said first token parameter size;

means for 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 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.

10. The apparatus of claim 9, wherein said traffic conditioner operates in a color aware mode when a packet of size B bytes arrives at time t, in accordance with the following steps:

if the packet is pre-colored as green and 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 packet has been pre-colored as green or yellow and 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 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.

11. The apparatus of claim 9, wherein said first and second token parameters correspond to first and second token buckets.

12. The apparatus of claim 9, wherein said at least one information rate is a in committed information rate.

13. The apparatus of claim 12, further including a peak information rate, wherein said second token count is incremented in accordance with a peak information rate up to said second token parameter size.

14. The apparatus of claim 13, wherein said first and second token parameters are initially full at time t equals zero and equal to peak bucket size (PBS) and a committed bucket size (CBS), respectively, wherein the first token count is incremented by one CIR times per second up to CBS and the second token count is incremented by one PIR times per second up to PBS.

15. The apparatus of claim 11, wherein said first and second token buckets are correspond to token buckets C and E, respectively, each token bucket having a respective token count Tc and Tc, wherein at time zero, the token count haves sizes Tc(0)=CBS and Te(0)=EBS and thereafter the token count Tc is incremented by one CIR times per second (up to CBS), and the token count Te is incremented by one EIR times per second (up to EBS), wherein in a Color-Aware mode the traffic conditioner when receiving a packet of size B operates as follows:

if the packet has been pre-colored as green and Tc(t)−

B>

=0, the packet is green and Tc is set to max(0, Tc(t)−

B);

else

if the packet has been pre-colored as green or yellow and if Tc(t)+Tc(t)−

B>

=0, the packet is yellow and Te is set to max(0, Te(t)−

B) and Tc is set to max(0, min(Tc(t), Tc(t)−

B+Te(t)));

else

the packet is red and neither Tc nor Te is decremented.

16. The apparatus of claim 15, wherein in a Color-Blind mode of operation, all incoming packets are treated as colored green.