Method and system for implementing end-to-end QoS in packet-switched networks

• US 6,674,760 B1
• Filed: 09/28/1999
• Issued: 01/06/2004
• Est. Priority Date: 09/28/1999
• Status: Expired due to Term

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Extreme Networks, Inc.
• Inventors: Gupta, Rajarshi, Walrand, Jean
• Primary Examiner(s): Vanderpuye, Kenneth
• Assistant Examiner(s): NGUYEN, BRIAN D
• Application Number:
  US09/407,205
• Time in Patent Office: 1,561 Days
• Field of Search: 370/411, 370/229, 370/230, 370/231, 370/232, 370/235, 370/352, 370/356, 370/386, 370/389, 370/392, 370/393, 370/394, 370/395.1, 370/395.21, 370/395.3, 370/395.4, 370/395.5, 370/395.52, 370/295.53, 370/400, 370/401, 370/455, 370/465, 370/471, 370/474, 370/475, 370/468, 370/469, 709/224, 709/225, 709/226, 709/229, 709/230, 709/238
• US Class Current: 370/411
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS

Abstract

Disclosed herein is a system and method to implement end-to-end QoS for connections in IP-based networks, even when the communications are between different subnetworks. In accordance with an embodiment of the invention, QoS is provided between subnet routers that are attached to the network through a network backbone. An embodiment of the invention can differentiate connections between routers and can classify data streams for both inter-subnet and intra-subnet connections using only information provided in the IP headers and without requiring any special tags or other identifiers to be added to the packet.

Claims

1. In a network including a plurality of subnetworks, a method of providing quality of service for packets transmitted inter-subnetwork and for packets transmitted intra-subnetwork, comprising:

receiving a packet at a first subnetwork of the plurality of subnetworks;

determining whether the received packet is an inter-subnetwork communication or an intra-subnetwork communication;

classifying the received packet into one of a plurality of quality of service classes based upon whether the packet is an inter-subnetwork communication or an intra-subnetwork communication and based upon the packet'"'"'s header information;

allocating resources necessary to provide a quality of service corresponding to the classified quality of service class; and

forwarding the packet to a next destination according to the packet'"'"'s classified quality of service class.

2. The method of claim 1, wherein the header information includes a source address, a destination address, and class of service bits.

3. The method of claim 2, wherein the destination address is represented by a virtual local area network (VLAN) identifier (ID).

4. The method of claim 1, wherein at least a portion of the packet'"'"'s header information is included in an Multiprotocol Label Switching (MPLS) tag.

5. A method of classifying packets in a network including a plurality of subnetworks, comprising:

receiving a packet at a first subnetwork of the plurality of subnetworks;

determining whether the packet is an inter-subnetwork communication or an intra-subnetwork communication;

classifying the packet to provide an appropriate level of quality of service based on the packet'"'"'s destination address and class of service identifier if the packet is an intra-subnetwork communication;

classifying the packet to provide an appropriate level of quality of service based on the packet'"'"'s source address, class of service identifier, and destination address if the packet is an inter-subnetwork communication; and

allocating resources necessary to provide the appropriate level of quality of service.

6. The method of claim 5, wherein classifying the packet to provide an appropriate level of quality of service based on the packet'"'"'s source address, class of service identifier, and destination address if the packet is an inter-subnetwork communication comprises classifying the packet to provide an appropriate level of quality of service based on the packet'"'"'s source address, class of service identifier, and a Virtual Local Area Network identifier (VLAN-ID) if the packet is an inter-subnetwork communication.

7. The method of claim 5, wherein the destination address and said class of service identifier are represented in an Multiprotocol Label Switching (MPLS) tag.

8. A method of classifying packets in a network including a plurality of subnetworks comprising:

receiving a packet at a first subnetwork of the plurality subnetworks;

determining whether the packet is an inter-subnetwork communication or an intra-subnetwork communication;

classifying the packet to provide an appropriate level of quality of service based on the packet'"'"'s class of service identifier and an incoming port at which the packet was received if the packet is an intra-subnetwork communication;

classifying the packet to provide an appropriate level of quality of service based on the packet'"'"'s class of service identifier, an incoming port at which the packet was received, and a Virtual Local Area Network identifier (VLAN-ID) if the packet is an inter-subnetwork communication; and

allocating resources necessary to provide the appropriate level of quality of service.

9. A network, comprising:

a backbone;

a plurality of border routers;

a plurality of user routers; and

a plurality of subnetworks, wherein each subnetwork includes a plurality of subnetwork nodes,

wherein each subnetwork node communicates with the backbone via a one or more of the plurality of border routers,

wherein each subnetwork node communicates with one or more Local Area Networks (LANs) or Virtual Local Area Networks (VLANs) via one or more of the plurality of user routers,

wherein each subnetwork node includes a classifier to classify packets for quality of service based on whether the packets are received from a border router or a user router and whether the received packets are intra-subnetwork communications or inter-network communications.

10. The network of claim 9, wherein the classifier to classify intra-subnetwork packets received at the node from a border router based on the packet'"'"'s destination address and class of service identifier.

11. The network of claim 10, wherein the classifier to further classify inter-subnetwork packets received at the node from a user router based on the packet'"'"'s destination address, class of service identifier, and an incoming port of the node at which the packet was received.

12. The network of claim 11, wherein the classifier to further classify intra-subnetwork packets received at the node from a user router based on the packet'"'"'s class of service identifier and an incoming port of the node at which the packet was received.

13. The network of claim 12, wherein the classifier to further classify inter-subnetwork packets received at the node from a border router based on the packet'"'"'s source address, destination address, and class of service.

14. The network of claim 12, wherein the classifier to further classify inter-subnetwork packets received at the node from a border router based on the packet'"'"'s source address, class of service, and a VLAN identifier (ID).

15. An article of manufacture comprising a machine accessible medium including content that when accessed by a machine causes the machine to:

receive a data packet at a first subnetwork in a network including a plurality of subnetworks;

determine whether the data packet is an inter-subnetwork communication or an intra-subnetwork communication;

classify the data packet into a quality of service class based on whether the data packet is an inter-subnetwork communication or an intra-subnetwork communication and based on the data packet'"'"'s header information;

allocate resources necessary to provide a quality of service corresponding to the classified quality of service class; and

forward the data packet to a next destination according to the data packet'"'"'s classified quality of service class.

16. The article of manufacture of claim 15, wherein the header information includes a source address, a destination address, and class of service bits.

17. The article of manufacture of claim 16, wherein the destination address is represented by a Virtual Local Area Network identifier (VLAN ID).