Quality of service (QoS) mechanism in an internet protocol (IP) network

• US 20040006613A1
• Filed: 07/03/2002
• Published: 01/08/2004
• Est. Priority Date: 07/03/2002
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lemieux, Yves, Elshabrawy, Tallal, Ashour, Mohamed
• Granted Patent: US 6,968,374 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 41/5022 by giving priorities, e.g. assigning classes of service
• CPC Class Codes: H04L 41/5041 characterised by the time relationship between creation and deployment of a service
• 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 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 45/507 Label distribution
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 47/2425 for supporting services specification, e.g. SLA
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/2458 Modification of priorities while in transit
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/724 at intermediate nodes, e.g. resource reservation protocol [RSVP]
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 47/825 Involving tunnels, e.g. MPLS

Abstract

The present invention provides a network node and corresponding methods for implementing a Quality of Service (QoS) mechanism in an Internet Protocol (IP) network. The network node comprises a swapping table comprising swapping records. Each swapping record lists an incoming network path and an associated QoS Class, an outgoing network path associated with the incoming network path. Each swapping records also lists a second QoS Class and an output port of the network node associated with the outgoing network path. The network node also comprises a communication module capable of receiving packet flows on one of the incoming network paths and directing the packets from the packet flows into packet queues each having an associated QoS classification corresponding to the QoS Class of the outgoing network path associated with the incoming network path on which the packets have been received, and as listed in the swapping table.

Claims

1. A network node for implementing a Quality of Service (QoS) mechanism in an Internet Protocol (IP) network, the network node comprising:

a plurality of packet queues for storing packets from incoming packet flows, each of the packet queues having an associated QoS classification;

a swapping table comprising swapping records, each of the swapping records listing an incoming network path and an associated QoS Class, an outgoing network path associated with the incoming network path, the outgoing network path having a second QoS Class associated therewith and an output port of the network node associated with the outgoing network path;

a communication module capable of;

receiving one of the incoming packet flows on one of the incoming network paths; and

directing the received packets from the incoming packet flow into one of the packet queues having the associated QoS classification corresponding to the QoS Class of the outgoing network path associated with the incoming network path on which the packets have been received, and as listed in the swapping table.

2. The network node of claim 1 where a plurality of the swapping records corresponds to one of the output ports.

3. The network node of claim 1 further comprising a port table comprising one port record for each of the output ports associated to one of the outgoing paths, each of the port records listing a plurality of QoS parameters for each of the corresponding output ports and a subsequent node associated with each of the output ports.

4. The network node of claim 3 where a plurality of the port records correspond to one of the output ports.

5. The network node of claim 3 where the communication module is further capable of detecting a modification in one of the port table or the swapping table and rebuilding a routing table to reflect the modification.

6. The network node of claim 1 where the communication module is further capable of forwarding the stored packets from the packet queues through one of the output ports associated to one of the outgoing paths, forwarding the stored packet being further based on the QoS classification associated therewith and on the swapping table?.

7. The network node of claim 1 where at least one of the incoming packet flows is received from an internal module of the network node.

8. The network node of claim 3 where the plurality of QoS parameters comprises at least two of the following:

a network metric;

a cost;

a delay;

a packet queue length;

a bandwidth;

a data loss probability; and

a delay-jitter.

9. The network node of claim 1 where the network node further comprises a routing table, the routing table comprising a routing record for other network nodes of the IP network.

10. The network node of claim 9 where the routing record comprises at least one best path toward each of the other network nodes, the at least one best path being associated with at least one of the plurality of QoS parameters.

11. The network node of claim 10, further comprising a quality module for managing the QoS mechanism, the quality module being capable of:

receiving a Status_request message on one of the incoming paths;

processing the Status_request message into a QoS Class_assignment message; and

sending the QoS Class_assignment message on one of the outgoing paths.

12. The network node of claim 11 where the Status_request message comprises at least one of the plurality of QoS parameters.

13. The network node of claim 11 where the QoS Class_assignment message comprises assigning one of the packet queues to the one of the incoming packet flows.

14. The network node of claim 3 where the communication module is further capable of:

receiving a Status_request, the Status_request comprising;

a list of network nodes to traverse;

at least one QoS parameter that needs improvement; and

an improvement value for each of the at least one QoS parameter;

responding to the Status_request by;

extracting a value of one of the plurality of QoS parameters listed in one of the port records corresponding to the at least one QoS parameter that needs improvement;

after extraction of the value, calculating a difference between the at least one QoS parameter that needs improvement and the value; and

after calculating the difference, filing the Status_request with the one of the plurality of QoS parameters listed in one of the port records and the difference; and

forwarding the Status_request to the next network node in the list of network nodes to traverse;

receiving a QoS Class_assignment message, the Class_assignment message comprising;

a list of network nodes to traverse; and

assignment of one of the packet queues to one of the incoming packet flows; and

responding to the QoS Class_assignment message by;

assigning the one of the packet queues to the one of the incoming packet flows; and

forwarding the QoS Class_assignment message to the next network node in the list of network nodes to traverse.

15. The network node of claim 1 where the network node further comprises a routing table, the routing table comprising a routing record for other network nodes of the IP network.

16. The network node of claim 15 where the routing record comprises at least one best path toward each of the other network nodes, the at least one best path being associated with at least one of the plurality of QoS parameters.

17. The network node of claim 16 where the communication module is further capable of:

identifying at least one QoS requirement associated with each of the incoming packet flows;

identifying a destination for each of the incoming packet flows; and

after identification of the destination, verifying that the at least one best path toward the destination meets the at least one QoS requirement.

18. The network node of claim 17 where the communication module is further capable of:

if the at least one best path toward the destination meets the at least one QoS requirement, sending an Information_request message on each of the output ports;

receiving at least one Information reply message in response to the Information_request message;

after reception of at least, one Information_reply message, identifying the at least one best path to be used; and

forwarding each of the incoming packet flows on the identified at least one best path.

19. The network node of claim 17 where the communication module is further capable of sending a reject message if the at least one best path toward the destination node does not meet the at least one QoS requirement.

20. The network node of claim 17 where the step of forwarding the packet flow on the identified best path further comprises forwarding the at least one QoS requirement on the identified best path.

21. The network node of claim 17 where identifying the at least one QoS requirement further comprises one of the following steps:

analyzing an existing Service Level Agreement (SLA) with a source of one of the incoming packet flows;

receiving the at least one QoS requirement in a traffic specification request from the source; and

identifying a type of traffic associated with the at least one QoS requirement for each of the incoming packet flows.

22. A method for having Quality of Service (QoS) mechanism on a network path in an Internet Protocol (IP) network, the network path having at least one network node thereon, the method comprising steps of:

at the network node, receiving a packet flow on the network path;

identifying at least one QoS requirement associated with the packet flow;

identifying a destination for the packet flow;

after identification of the destination, verifying in a routing table of the network node that at least one best path toward the destination meets the at least one QoS requirement;

if the at least one best path toward the destination meets the at least one QoS requirement, sending an Information_request message on at least one output port of the network node toward at least one target node;

at the network node, receiving at least one Information_reply message from the at least one target node in response to the Information_request message;

after reception of the Information_reply from the at least one target node, identifying the best path to be used; and

forwarding the packet flow from the network node on the identified best path.

23. The method of claim 22 where the routing table comprises a routing record for other network nodes in the 1P network.

24. The method of claim 23 where the routing record comprises the at least one best path toward the other network nodes, the at least one best path being associated with at least one of a plurality of QoS parameters.

25. The method of claim 24 where the plurality of QoS parameters comprises at least two of the following:

a network metric;

a cost;

a delay;

a packet queue length;

a bandwidth;

a data loss probability; and

a delay-jitter.

26. The method of claim 22 where the step of forwarding the packet flow on the identified best path further comprises forwarding the at least one QoS requirement on the identified best path.

27. The method of claim 22 where identifying the at least one QoS requirement further comprises one of the following steps:

analyzing an existing Service Level Agreement (SLA) with a source the packet flow;

receiving the at least one QoS requirement in a traffic specification request from the source; and

identifying a type of traffic associated with the at least one QoS requirement for the packet flow.

28. A method for implementing a Quality of Service (QoS) mechanism for transiting packet flows between a first network node and a second network node in an Internet Protocol (IP) network, each of the packet flows having at least one QoS requirement associated therewith, the IP network comprising at least another network node and network paths connecting two of the network nodes, each of the packet flows transiting from the first network node on one of the network paths up to the at least another network node and on one other of the network paths up to the second network node, the method comprising steps of:

identifying a problem with transiting one of the packet flows;

at the first network node, sending a Status request message on the one of the network paths connected thereto toward the second network node;

at the at least another network node, filing the received Status_request message with availability information extracted from a port table;

at the second network node, processing the availability information from the Status_request message into a Class_assignment message; and

at the second network node, forwarding the Class_assignment message on the one other of the network paths connected thereto toward the first network node.

29. The method of claim 28 where the step of identifying a problem for transiting one of the packet flows comprises at least one step of

receiving at the first network node an Explicit_request from the at least another network node;

calculating at the first network node a value for a QoS parameter between the first and the second network nodes corresponding to the at least one QoS requirement associated to the one of the packet flows; and

after calculating the value, identifying at the first network node that the at least one QoS requirement associated to the one of the packet flows is not met.

30. The method of claim 29 where the QoS parameters is one of the following:

a network metric;

a cost;

a delay;

a packet queue length;

a bandwidth;

a data loss probability; and

a delay-jitter.

31. The method of claim 28 where the step of identifying a problem for transiting one of the packet flows comprises at least one step of

receiving at the second network node an Explicit_request from the at least another network node;

calculating at the second network node a value for a QoS parameter between the first and the second network nodes corresponding to the at least one QoS requirement associated to the one of the packet flows; and

after calculating the value, identifying at the second network node that the at least one QoS requirement associated to the one of the packet flows is not met.

32. The method of claim 31 where the QoS parameters is one of the following:

a network metric;

a cost;

a delay;

a packet queue length;

a bandwidth;

a data loss probability; and

a delay-jitter.

33. The method of claim 28 where the port table further comprises one port record for each output ports of the at least another network nodes associated to one of the network paths, each of the port records listing a plurality of QoS parameters for each of the corresponding output ports and a subsequent network node associated with each of the output ports.

34. The network node of claim 33 where a plurality of the port records corresponds to one of the output ports.

35. The method of claim 33 where the Status_request further comprises

a list of network nodes to traverse toward the second network node;

at least one QoS parameter that needs improvement; and

an improvement value for each of the at least one QoS parameter.

36. The method of claim 35 where the step of filing the Status_request message with availability information extracted from the port table further comprises steps of:

at the at least another network node, receiving the Status_request on the one other of the network paths;

after reception of the Status_request, extracting a value of one of the plurality of QoS parameters listed in one of the port records where the output port of the one of the port records corresponds to the output port of the one other of the network paths;

after extraction of the value, calculating a difference between the at least one QoS parameter that needs improvement and the value; and

after calculating the difference, filing the status request with the one of the plurality of QoS parameters listed in one of the port records and the difference.

37. The method of claim 28 where the step of processing the availability information from the Status_request message into the Class_assignment message further comprises steps of:

extracting the availability information from the Status_request;

identifying which of the at least one network node is to change its current Class_assignment; and

issuing the Class_assignment message toward the first network node.

38. The method of claim 28 where the Status_request message further contains information found in a ReSerVation Protocol—

Traffic Engineering (RSVP-TE) PATH message.

39. The method of claim 28 where the Class_assignment message further contains information found in a ReSerVation Protocol—

Traffic Engineering (RSVP-TE) RESERVE message.