System and Method for Priority Based Flow Control Between Nodes

• US 20130003550A1
• Filed: 08/26/2011
• Published: 01/03/2013
• Est. Priority Date: 06/29/2011
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Winegarden, Colin, Kelley, Daniel, Babu, Biju
• Granted Patent: US 9,124,524 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 12/56 Packet switching systems
• 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 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/03 by updating link state protocols
• CPC Class Codes: H04L 45/122 by minimising distances, e.g. by selecting a route with minimum of number of hops
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 45/48 Routing tree calculation

Abstract

A system and method for priority-based flow control between nodes. In one example, pause deadlocks in a physical loop can be averted by priority-based selection of egress ports to which a packet is forwarded. In one embodiment, if the packet priority matches a configured lossless priority, then the set of internal egress ports is masked such that only the internal ports belonging to the spanning tree remain in the set of internal egress ports. If the packet priority does not match a configured lossless priority, then the set of internal egress ports is masked such that only the internal ports belonging to the shortest path first tree remain in the set of internal egress ports.

Claims

1. A priority based flow control method in a network node, comprising:

receiving a packet on an ingress port of said network node;

identifying a packet priority of said received packet;

identifying a forwarding tree to apply to said received packet based on said identified packet priority; and

forwarding said received packet to a set of egress ports being determined based on said identified forwarding tree.

2. The method of claim 1, wherein said identifying comprises identifying a packet priority using a type of service field in said received packet.

3. The method of claim 1, wherein said identifying comprises identifying a packet priority using a differentiated services code point field in said received packet.

4. The method of claim 1, wherein said forwarding comprises forwarding using a spanning tree.

5. The method of claim 1, wherein said forwarding comprises forwarding using a shortest path first tree.

6. A priority based flow control method in a network node, comprising:

receiving a packet on an ingress port of said network node;

identifying a packet priority of said received packet;

identifying a set of internal egress ports to which said received packet is to be forwarded;

modifying said set of internal egress ports based on said identified packet priority; and

forwarding said received packet to said modified set of said internal egress ports.

7. The method of claim 6, wherein said identifying comprises identifying a packet priority using a type of service field in said received packet.

8. The method of claim 6, wherein said identifying comprises identifying a packet priority using a differentiated services code point field in said received packet.

9. The method of claim 6, wherein said modifying comprises modifying said set of internal egress ports based on a spanning tree.

10. A priority based flow control method in a network system, comprising:

identifying a plurality of network nodes in said network system; and

transmitting, from a system manager to each of said plurality of network nodes, configuration information that enables each of said plurality of network nodes to implement a flow control process, said flow control process enabling each of said plurality of network nodes to identify one of a plurality of forwarding trees for application to a received packet, said identified on of said plurality of forwarding trees being based on a traffic priority of said received packet.

11. The method of claim 10, wherein said plurality of forwarding trees includes a spanning tree and a shortest path first forwarding tree.