System and method for transmitting data packets in an infiniband network

• US 7,512,134 B2
• Filed: 12/08/2004
• Issued: 03/31/2009
• Est. Priority Date: 12/30/2003
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schiller, Claudiu, Shalev, Leah
• Primary Examiner(s): Kizou; Hassan
• Assistant Examiner(s): Rutkowski; Jeffrey M
• Application Number:
  US10/904,979
• Publication Number:
  US 20050141518A1
• Time in Patent Office: 1,574 Days
• Field of Search: 370/395.1, 370/419, 370/389, 370/395.2, 370/357, 370/397, 370/235, 709/238, 710/100, 326/40
• US Class Current: 370/395.31
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/35 Switches specially adapted for specific applications
• CPC Class Codes: H04L 49/358 Infiniband Switches

Abstract

The disclosed invention relates to a method and system to transmit data packets through a switched network system that is composed of a plurality of routing entities. The method determines whether or not the output port assigned to the data packet and the associated input port are local to the routing entity by referencing an index pointer to a routing table.

Claims

1. A method for transmitting a data packet received at a first routing entity in a switched network system having at least a Service Level to Virtual Lane (SL-to-VL) mapping table and comprising a plurality of input ports coupled to a plurality of output ports by multiple routing entities, the method comprising:

a) assigning an output port to the data packet from a switch routing table associated with the switched network system;

b) determining whether an output port is coupled to the first routing entity;

c) assigning a local output port to the data packet from a local routing table associated with a first routing entity if the output port previously obtained is not coupled to the first routing entity;

d) determining whether an input port is coupled to the first routing entity;

e) associating a Virtual Lane (VL) to the data packet from the SL-to-VL mapping table if the input port is not coupled to the first routing entity; and

f) placing the data packet in a VL queue buffer.

2. The method according to claim 1, wherein the step assigning a data packet to a local output port using a switch routing table further comprises using a Destination Local Identifier (DLID) of the data packet to point to an index in the switch routing table.

3. The method according to claim 1, wherein the step of assigning a local output port to the data packet from a local routing table associated with the first routing entity further comprises using the output port obtained in the step assigning an output port to the data packet from a switch routing table associated with the switched network system.

4. The method according to claim 1 wherein the step of assigning a local output port to the data packet from a local routing table associated with the first routing entity further comprises using the output port obtained in the step assigning an output port to the data packet from a switch routing table associated with the switched network system combined with the DLID to point to the local routing table.

5. The method according to claim 1 further comprising the step of forwarding the data packet out

of the switched network system to a final destination address.

6. The method according to claim 1 wherein the data packet is a unicast data packet.

7. The method of according to claim 1 wherein the data packet is a multicast data packet.

8. The method according to claim 1 wherein the switched network system comprises a switch node of a scalable switched fabric communication link with point-to-point bi-directional serial interconnect and associated protocol.

9. The method of claim 8 wherein the scalable switched fabric communication link with point-to-point bi-directional serial interconnect and associated protocol comprises one or more switched network systems.

10. The method according to claim 1, further comprising a switching controller having a system management capability to execute the transfer of data packets in the switched network system.

11. The method according to claim 1, wherein the first routing entity comprises a switch.

12. The method according to claim 1, wherein the multiple routing entities comprise a plurality of interconnected multi-port switches.

13. A computer readable medium, tangibly embodying an executable program of instructions causing a computer to perform method steps for transmitting a data packet in a switched network system, the method steps comprising:

a) assigning an output port to the data packet from a switch routing table associated with the switched network system;

b) determining whether an output port is coupled to the first routing entity;

c) assigning a local output port to the data packet from a local routing table associated with the first routing entity if the output port previously obtained is not coupled to the first routing entity;

d) determining whether an input port is coupled to the first routing entity;

e) associating a VL to the data packet from the SL-to-VL mapping table if the input port is not coupled to the first routing entity; and

f) placing the data packet in a VL queue buffer.

14. A method of routing data packets through a high speed communications switch fabric, comprising:

receiving a first data packet from an external link of the switch fabric at a first input port;

extracting a destination local identifier (DLID) from a header field within the first data packet;

obtaining a first output port identifier using the extracted DLID as an index to point to a first mapping table associated with the switch fabric; and

determining whether the first output port identifier corresponds to a local output port of the switch fabric,

wherein if the first output port is local to the switch fabric;

determining whether the first output port identifier is mapped to an internal port or external port of the switch fabric,

assigning a SL to VL mapping based on a service level (SL) associated with the first data packet, a first input port identifier and the first output port identifier, and

forwarding the first data packet with the SL to VL mapping out of the switch fabric, or

wherein if the first output port identifier obtained from the first mapping table is external to the switch fabric;

assigning a second output port identifier to the first data packet by indexing the first output port identifier to a second mapping table associated with the switch fabric.