Granted Patent B1

US 7,609,710 · App. 12/019,094 · Granted Oct 27, 2009

Abstract

Claims (20)

1. A method for credit management in a network system, comprising:

receiving an incoming frame at a receive port of a network device;

determining a frame length of the incoming frame;

based on the frame length, determining whether to store the frame in a first memory storage space or a second memory storage space, wherein the first memory storage space includes a plurality of slots and each of the plurality of slots can store only one frame regardless of frame size; and the second memory storage space includes a plurality of slots and each of the plurality of slots can store more than one frame; if the incoming frame is stored in the second memory storage space, transmitting a signal immediately to another port indicating that credit is available; and if the incoming frame is stored in the first memory storage space, transmitting a signal to another port indicating that credit is available only after a frame has been processed so that a slot is released from the first memory storage space.

2. The method of claim 1 , wherein the first memory storage space is a receive buffer at a receive port of a network switch and the second memory storage space is a first-in-first out buffer (FIFO) at the receive port.

3. The method of claim 2 , wherein the network switch is a Fibre Channel switch.

4. The method of claim 3 , wherein the signal indicating credit is a R_RDY primitive used in a Fibre Channel network.

5. The method of claim 3 , wherein the signal indicating credit is a VC_RDY primitive used in a Fibre Channel network that supports virtual lanes.

6. The method of claim 1 , wherein a frame monitoring logic monitors the incoming frame and based on frame size determines if the incoming frame can be stored in the second memory storage space.

7. The method of claim 1 , wherein the network switch is one or more of an InfiniBand switch and an Ethernet switch.

8. A buffer structure for a network port, comprising:

a frame monitoring logic for monitoring and determining a frame length of an incoming frame received at the network port;

a first memory storage space that includes a plurality of slots, where each of the plurality of slots can store only one frame regardless of frame size; and

a second memory storage space that includes a plurality of slots, where each of the plurality of slots can store more than one frame; wherein depending on the frame length, the incoming frame is either stored in the first memory storage space or the second memory storage space; if the incoming frame is stored in the second memory storage space, a signal is immediately transmitted to another port indicating that credit is available to store more frames; and if the incoming frame is stored in the first memory storage space, transmitting a signal to another port indicating that credit is available to store more frames only after a frame has been processed so that a slot is released from the first memory storage space.

9. The structure of claim 8 , wherein the first memory storage space is a receive buffer at a receive port of a network switch and the second memory storage space is a first-in-first out buffer (FIFO) at the receive port.

10. The structure of claim 9 , wherein the network switch is a Fibre Channel switch.

11. The structure of claim 9 , wherein the network switch is a Ethernet switch.

12. The structure of claim 10 , wherein the signal indicating credit is a R_RDY primitive used in a Fibre Channel network.

13. The structure of claim 12 , wherein the signal indicating credit is a VC_RDY primitive used in a Fibre Channel network that supports virtual lanes.

14. The structure of claim 8 , wherein the network port is a part of an InfiniBand switch.

Assignments (6)