Distributed quality-of-service system

• US 7,149,795 B2
• Filed: 09/18/2001
• Issued: 12/12/2006
• Est. Priority Date: 09/18/2000
• Status: Active Grant

• Current Assignee: Barracuda Networks Incorporated
• Original Assignee: Converged Access, Inc.
• Inventors: Sridhar, Manickam R., Steckel, Geoff
• Primary Examiner(s): Dharia, Rupal
• Assistant Examiner(s): Tran, Nghi V.
• Application Number:
  US09/955,860
• Publication Number:
  US 20020073226A1
• Time in Patent Office: 1,911 Days
• Field of Search: 709/223, 709/233, 709/238, 709/220, 709/250, 714/13
• US Class Current: 709/223
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 41/5003 Managing SLA; Interaction between SLA and QoS
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04L 45/30 Routing of multiclass traffic
• CPC Class Codes: H04L 45/308 Route determination based on user's profile, e.g. premium users
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/13 in a LAN segment, e.g. ring or bus
• CPC Class Codes: H04L 47/20 Traffic policing
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A distributed quality-of-service system makes use of a distributed architecture to achieve very high throughput and availability in which a number of separate processors are loosely coupled in a scalable communication architecture. The computational load required to implement an approach that is similar to that of Floyd and Jacobson is distributed among the processors without requiring the processors to be tightly coupled. A high data rate flow is split so that each processor receives a portion of the traffic passing through the system. The processors implement separate class-based queuing and link fairness algorithms. The output flows of each of the processors are combined to form the overall output flow. The processors exchange data from time to time in order to achieve an approximate link fairness on the overall output flow without requiring the separate algorithms implemented on each of the processors to be tightly coupled.

Claims

1. A communication system for implementing an overall communication policy comprising:

a first communication interface for accepting a first plurality of separate communication links forming a first trunked communication link;

a second communication interface for accepting a second plurality of separate communication links forming a second trunked communication link; and

a plurality of processors, each coupled to a corresponding different one of the first plurality of separate communication links and coupled to a corresponding different one of the second plurality of communication links, and coupled to one another over a communication channel;

wherein each processor in the plurality of processors is configured to implement a separate communication policy for data passing between one of the first plurality of communication links forming the first trunked communication link and a corresponding one of the second plurality of communication links forming the second trunked communication link, such that together the separate communication policies approximate the overall communication policy,

wherein the plurality of processors are further configured to communicate among one another to adjust the separate communication policies to adapt to data flows passing through the processors,

wherein each processor in the plurality of processors has a copy of each communication policy in the communication system and communicates with the other processors in the plurality of processors to keep state information current for each such copy, and

wherein the plurality of processors is divided into a plurality of active processors and a plurality of standby processors, such that each processor in the plurality of active processors actively implements a communication policy on data, while a standby processor in the plurality of standby processors monitors the plurality of active processors for a failure on an active processor, and upon detecting the failure the standby processor joins the plurality of active processors, thus implementing the overall communication policy.

2. The system of claim 1, wherein adapting to data flows includes a first processor in the plurality of processors borrowing bandwidth from a second processor in the plurality of processors.

3. The system of claim 1, wherein each processor in the plurality of processors mirrors state information for reporting across the communication system.

4. The system of claim 1, wherein each processor in the plurality of processors mirrors state information for management across the communication system.

5. The system of claim 1, wherein the overall communication policy is only implemented for traffic traveling from the first interface to the second communication interface.

6. The system of claim 1, wherein the overall communication policy is implemented for traffic traveling between the first interface and the second communication interface in either direction.

7. A communication system for implementing an overall communication policy comprising:

a first communication link;

a second communication link;

a plurality of processors, each processor in the plurality of processors configured to implement the communication policy for data passing between the first communication link and the second communication link;

a first plurality of aggregator/disaggregator network devices arranged between the plurality of processors and the first communication link;

a second plurality of aggregator/disaggregator network devices arranged between the plurality of processors and the second communication link;

a first mesh, including a plurality of network links such that a link in the plurality of network links exists to join each processor in the plurality of processors to each aggregator/disaggregator in the first plurality of aggregator/disaggregator network devices; and

a second mesh, including a plurality of network links such that a link in the plurality of network links exists to join each processor in the plurality of processors to each aggregator/disaggregator in the second plurality of aggregator/disaggregator network devices;

wherein each processor in the plurality of processors is configured to implement a separate communication policy for data passing between the first communication link via a first aggregator/disaggregator in the first plurality of aggregator/disaggregator network devices and the second communication link via a corresponding one of the second plurality of aggregator/disaggregator network devices, such that together the separate quality-of-service policies approximate the overall communication policy,

wherein the plurality of processors are further configured to communicate among one another to adjust the separate communication policies to adapt to data flows passing through the processors, and

wherein the plurality of processors is divided into a plurality of active processors and a plurality of standby processors, such that each processor in the plurality of active processors actively implements a communication policy on data, while a standby processor in the plurality of standby processors monitors the plurality of active processors for a failure on an active processor, and upon detecting the failure the standby processor joins the plurality of active processors, implementing a communication policy on data previously associated with the active processor.

8. The system of claim 7, wherein each processor in the plurality of processors has a copy of each communication policy in the communication system and communicates with the other processors in the plurality of processors to keep state information current for each such copy.