Method and system for programmable data dependant network routing

• US 7,646,767 B2
• Filed: 07/20/2004
• Issued: 01/12/2010
• Est. Priority Date: 07/21/2003
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: QLogic Corporation (Marvell Technology Group Limited)
• Inventors: Dropps, Frank R, Betker, Steven M, McGlaughlin, Edward C
• Primary Examiner(s): Moe; Aung S
• Assistant Examiner(s): Grey; Christopher P
• Application Number:
  US10/894,978
• Publication Number:
  US 20050030954A1
• Time in Patent Office: 2,002 Days
• Field of Search: 370/60, 370/216, 370/252, 370/321, 370/352, 370/401, 370/469, 370/395.32, 370/395.31, 370/429, 370/359, 370/389, 370/392, 370/404, 370/428, 370/474, 709/203, 709/208, 709/213, 709/226, 709/231, 709/245, 709/246, 710/36
• US Class Current: 370/389
• 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 45/24 Multipath
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 49/101 using crossbar or matrix

Abstract

A method and system for routing fiber channel frames using a fiber channel switch element is provided. The switch element includes, a hashing module whose output is used to select the column from a look up table to route frames. The method includes, indexing a look up table using domain, area, virtual storage area network identifier, a hashing module output and/or AL_PA values; selecting a column from the look up table based on a column select signal; and routing a frame if a route is valid. The hashing module takes a fiber channel header to generate a pseudo random value used for selecting a column from the look up table. The hashing module uses same field values in an exchange to generate the pseudo random value. A hash function is used on a frame'"'"'s OX_ID, D_ID, S_ID, and/or RX_ID to route fiber channel frames.

Claims

1. A method for routing fibre channel frames using a fibre channel switch element, comprising:

(a) receiving a fibre channel frame at a port of the fibre channel switch element;

(b) indexing a look up table by using an output value generated by a hashing module for the fibre channel switch element;

a domain value for routing the fibre channel frame to another fibre channel switch, an area value for routing the fibre channel frame to a port of the fibre channel switch that received the fibre channel frame, a virtual storage area network identifier for routing the fibre channel frame within a virtual storage area network, and an arbitrated loop physical address (AL_PA) value included in a header of the fibre channel frame;

(c) selecting a column value from the look up table based on a column select signal generated by a hardware logic;

wherein the column select signal is based on the output value generated by the hashing module; and

wherein the output value is a pseudo random number value generated by the hashing module by applying a hash function on a field of a fibre channel frame header of the fibre channel frame; and

the pseudo random number value is used for selecting the column value used for routing the frame; and

(d) based on the selected column value, routing the frame if a route is valid.

2. The method of claim 1, wherein the hashing module uses a same field value from the fibre channel frame header for a same fibre channel exchange to generate the pseudo random number value.

3. The method of claim 1, wherein the hash function is applied on an originator exchange identification field (OX_ID of the fibre channel frame to route the fibre channel frame.

10. The method of claim 1, wherein the bash function to route the fibre channel frame is used on at least one or more of a destination identifier field (D_ID), a source identifier field (S_ID) and a responder exchange identifier field (RX_ID), included in the fibre channel frame header for the fibre channel frame.

11. The method of claim 1, wherein the column select signal is generated after a plurality of fields are input to the hardware logic and one of the input fields is selected to generate the column select signal.

12. The method of claim 11, wherein the hardware logic is a multiplexer and the plurality of inputs are a destination identifier field (D_ID), a source identifier field (S_ID), a virtual storage area network identifier, an originator exchange identification field (OX_ID), the pseudo random number generated by the hashing module, and a decode fibre channel header type field.

4. A fibre channel switch element configured to select a route from amongst a plurality of routes, for routing fibre channel frames, the fibre channel switch element comprising:

at least one port for receiving and transmitting a fibre channel frame;

a look up table with a plurality of columns that are indexed by an output from a hashing module, a domain value for routing the fibre channel frame to another fibre channel switch element, an area value for routing the fibre channel frame to a port of the fibre channel switch that received the fibre channel frame, a virtual storage area network identifier for routing the fibre channel frame within a virtual storage area network and an arbitrated loop physical address (AL^—

PA) value; and

a hardware logic that receives a plurality of inputs and based on one of the inputs, a column select signal is generated, wherein the column select signal is used to select a value from one of toe plurality of columns to route the fibre channel frame; and

wherein the column select signal is based on the output value generated by the hashing module; and

wherein the output value is a pseudo random number value generated by the hashing module by applying a hash function on a field of a fibre channel frame header of the fibre channel frame for selecting the column value.

5. The fibre channel switch element of claim 4, wherein the hashing module uses a same field value from the fibre channel frame header for a same fibre channel exchange to generate the pseudo random number value.

6. The fibre channel switch element of claim 4, wherein the hash function is applied on an originator exchange identification field (OX_ID) of the fibre channel frame to route the fibre channel frame.

7. The fibre channel switch element of claim 4, wherein the hash function, to route the fibre channel frame, is used on at least one or more of a destination identifier field (D_ID), a source identifier field (S_ID) and a responder exchange identifier field (RX_ID), included in the fibre channel frame header for the fibre channel frame.

8. The fibre channel switch element of claim 4, wherein the hardware logic is a multiplexer and be plurality of inputs are a destination identifier field (D_ID), a source identifier field (S_ID), a virtual storage area network identifier, an originator exchange identification field (OX_D), the pseudo random number value generated by the hashing module, and a decode fibre channel header type field.

9. The fibre channel switch element of claim 8, wherein the decode fibre channel header type field is decoded and then a derived value is used to select a column from the look table.

13. A network system, comprising:

host computing system for sending and receiving information;

a least one storage system for storing information; and

a least one fibre channel switch element configured to select a route from amongst a plurality of routes, for routing fibre channel frames in the network, where the fibre channel switch element includes;

(a) at least one port for receiving and transmitting a fibre channel frame;

(b) a look up table with a plurality of columns that are indexed by an output from a hashing module, a domain value for routing the fibre channel frame to another fibre channel switch element, an area value for routing the fibre channel frame to a port of the fibre channel switch that received the fibre channel frame, a virtual storage area network identifier for routing the fibre channel frame within a virtual storage area network and an arbitrated loop physical address (AL_PA) value; and

c) a hardware logic that receives a plurality of inputs and based on one of the inputs, a column select signal is generated, wherein the column select signal is used to select a value from one of the plurality of columns to route the fibre channel frame; and

wherein the column select signal is based on the output value generated by the hashing module; and

wherein the output value is a pseudo random number value generated by the hashing module by applying a hash function on a field of a fibre channel frame header of the fibre channel frame for selecting the column value.

14. The system of claim 13, wherein the hashing module uses a same field value from the fibre channel frame header for a same fibre channel exchange to generate the pseudo random number value.

15. The system of claim 13, wherein the hash function, to route the fibre channel frame, is used on at least one or more of originator exchange identification field (OX_ID), a destination identifier field (D_ID), a source identifier field (S_ID and a responder exchange identifier field (RX_ID), included in a fibre channel frame header for the fibre channel frame.

16. The system of claim 13, wherein the hardware logic is a multiplexer and the plurality of inputs are a destination identifier field (D_ID) a source identifier field (S_ID), a virtual storage area network identifier, an originator exchange identification field (OX_ID), the pseudo random number value generated by the hashing module, and a decode fibre channel header type field.