Method and system for controlling packet flow in networks

• US 7,319,669 B1
• Filed: 11/22/2002
• Issued: 01/15/2008
• Est. Priority Date: 11/22/2002
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: QLogic Corporation (Marvell Technology Group Limited)
• Inventors: Kunz, James A., Owen, Mark A., Haseman, Leonard W., Gustafson, William J.
• Primary Examiner(s): Hsu; Alpus H.
• Application Number:
  US10/302,149
• Time in Patent Office: 1,880 Days
• Field of Search: 370/235, 370/395.42, 370/409, 370/412, 370/428
• US Class Current: 370/235
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/6255 queue load conditions, e.g. longest queue first
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9078 using an external memory or storage device

Abstract

A system and method for transmitting and bundling network packets is provided. The incoming network packet size is determined and if the remote buffer space is sufficient to hold the network packet it is transmitted to the destination port. If the remote buffer space is not enough to hold the network packet it is discarded. The system includes an arbitration module that receives remote buffer space information and transmits the network packet if the remote buffer space has enough space to hold the packet. The arbitration module also determines if a second network packet is from a same source port having a same source virtual lane, and has the same destination virtual lane (bundling conditions). If the second network packet meets the bundling conditions, then it is transmitted after the first network packet, even if other packets were received before the second network packet.

Claims

1. A method for transmitting a plurality of network packets, comprising:

(a) receiving network packet information for transmitting a network packet from one of the plurality of network packets that are waiting to be transmitted at a given time;

wherein an arbitration module of a network switch receives the network packet information that includes information regarding network packet size;

(b) obtaining information regarding a remote buffer at a destination port where the network packet is to be sent;

wherein the arbitration module obtains the information regarding the remote buffer;

(c) determining if available space in the remote buffer is sufficient to hold the network packet; and

(d) transmitting the network packet via a virtual lane to the destination port, if the network packet can be stored in available space in the remote buffer.

2. The method of claim 1, further comprising:

selecting another network packet from the plurality of network packets and repeating steps (a) to (d), if available space in the remote buffer is not enough to hold the network packet.

3. The method of claim 1, wherein the network switch is an Infiniband switch.

4. The method of claim 1, wherein a network packet tag includes information regarding network packet size and information regarding a receive port where the network packet is waiting to be fetched for transmission and the arbitration module uses the network tag information and generates a packet request to transmit the network packet.

5. The method of claim 1, wherein the arbitration module selects a network packet from among the plurality of network packets based on a priority table that stores information to categorize a network packet as a high priority network packet or a low priority packet;

and the priority table stores a value for limiting transmission of high priority network packets before transmitting a low priority network packet that is waiting for transmission at any given time.

6. The method of claim 5, wherein a low priority network packet is transmitted if there is no high priority network packet waiting for transmission;

or if a period to transmit a high priority network packet has exceeded the value in the priority table to limit transmission of high priority network packets.

7. The method of claim 5, wherein the arbitration module transmits a second network packet after a first network packet even if other network packets that were received before the second network packet are waiting for transmission, if the second network packet is received from a same source as the first network packet;

the second network packet is destined for a same destination as the first network packet and the second network packet is received in a consecutive order after the first network packet.

11. The system of claim 3, wherein the network switch is an Infiniband switch.

8. A system for transmitting a plurality of network packets, comprising:

a receive port of a network port in a network switch that receives a network packet and generates a packet descriptor and packet size information;

a transmit port of the network port of the network switch that receives a packet tag with the packet descriptor and packet size information; and

an arbitration module that selects a network packet from among the plurality of network packets that are waiting to be transmitted at a given time, obtains information regarding available space in a remote buffer and compares the packet size information with the available space in the remote buffer and transmits the network packet via a virtual lane if the available space in the remote buffer is large enough to hold the network packet.

9. The system of claim 8, wherein the network port stores an arbitration priority table that stores information to categorize a network packet as a high priority network packet or a low priority packet;

and the priority table stores a value for limiting transmission of high priority network packets before transmitting a low priority network packet that is waiting for transmission at any given time via a virtual lane.

10. The system of claim 9, wherein a low priority network packet is transmitted via a virtual lane if there is no high priority network packet waiting for transmission;

or if a high priority transmit period has exceeded the value in the priority table that limits transmission of high priority network packets.

12. The system of claim 8, wherein the arbitration module transmits a second network packet after a first network packet even if other network packets that were received before the second network packets are waiting for transmission, if the second network packet is received from a same source as the first network packet;

the second network packet is destined for a same destination as the first network packet and the second network packet is received in a consecutive order after the first network packet.

13. A system for network transmission, comprising:

a first network switch communicating with a second network switch;

wherein the first network switch comprises a receive port of a network port in the first network switch that receives a network packet and generates a packet descriptor and packet size information;

a transmit port of the network port of the first network switch that receives a packet tag with the packet descriptor and packet size information; and

an arbitration module for the network port of the first network switch that determines if a second network packet is from a same source port having a same source virtual lane and destination virtual lane and was received in a consecutive order, and transmits the second network packet after the first network packet, even if other packets were received before the second network packet and are waiting to be sent, wherein the network port for the first network switch stores an arbitration priority table that stores information to categorize a network packet as a high priority network packet or a low priority packet; and

the priority table stores a value for limiting transmission of high priority network packets before transmitting a low priority network packet that is waiting for transmission at any given time.

14. The system of claim 13, wherein a low priority network packet is transmitted if there is no high priority network packet waiting for transmission;

or if a high priority transmit period has exceeded the value in the priority table that limits transmission of high priority network packets.

15. The system of claim 13, wherein the network switch is an Infiniband switch.