Method and system for routing and filtering network data packets in fibre channel systems

• US 20050044267A1
• Filed: 07/20/2004
• Published: 02/24/2005
• 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., Ross, Edward C., Betker, Steven M.
• Granted Patent: US 7,792,115 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC

Abstract

A fibre channel switch element with an alias cache is provided for routing and filtering frames. The alias cache includes plural entries including a control word having plural fields including an action code for routing frames; an alias word that is compared to incoming frame data using a frame byte compare block; and a bit mask generator for filtering bit combinations from the frame byte compare block; and a depth match block for determining equality between a control word depth field and incoming frame depth field. Frame data comparison is performed on a bit by bit or byte-by-byte basis. An alias cache entry also includes prerequisite data to determine if results of a different entry are to be used to determine an entry match. The action code routes a frame to a processor, discards a frame, sets a status for inspecting a frame or routes a frame based on a standard Fibre Channel addressing scheme.

Claims

1. A method for routing and filtering frames in a fibre channel switch, comprising:

comparing incoming frame data to plural alias cache entries at the same time;

performing a word depth match by comparing incoming frame word depth with a programmed word depth; and

routing frames based on a programmed action code that is a part of an alias cache entry.

2. The method of claim 1, where the frame data comparison is performed on a bit by bit or byte-by-byte basis.

3. The method of claim 1, wherein an action code routes a frame to a specified destination, discards a frame, sets a status for inspecting a frame or routes a frame based on a standard Fibre Channel addressing scheme.

4. The method of claim 1, wherein an alias cache entry includes prerequisite data to determine if a different entry'"'"'s compare results at a different fame word depth are to be used to determine an entry match.

19. The method of claim 1, wherein plural frame words are compared before any action is taken.

5. A system for routing and filtering frames in a fibre channel switch, comprising:

an alias cache with an alias cache entry, where the alias cache entry includes, a control word having plural fields including an action code for routing frames;

an alias word that is compared to incoming frame data using a frame byte compare block;

and a bit mask generator for filtering bit combinations from the frame byte compare block; and

a depth match block for determining equality between a control word depth field and incoming frame depth field.

6. The system of claim 5, further comprising:

a valid and status generator module that receives plural inputs and generates an output signal that is sent to an encoder module.

7. The system of claim 5, where the frame data comparison is performed on a bit by bit or byte-by-byte basis.

8. The system of claim 5, wherein an action code routes a frame to a processor, discards a frame, sets a status for inspecting a frame or routes a frame based on a standard Fibre Channel addressing scheme.

9. The system of claim 5, wherein an alias cache entry includes prerequisite data to if a different entry'"'"'s compare results at a different fame word depth are to be used to determine an entry match.

20. The system of claim 5, wherein plural frame words are compared before any action is taken.

10. A fibre channel switch element for routing and filtering frames in a fibre channel network, comprising:

an alias cache with an alias cache entry, where the alias cache entry includes, a control word having plural fields including an action code for routing frames;

an alias word that is compared to incoming frame data using a frame byte compare block;

and a bit mask generator for filtering bit combinations from the frame byte compare block; and

a depth match block for determining equality between a control word depth field and incoming frame depth field.

11. The switch element of claim 10, further comprising:

a valid and status generator module that receives plural inputs and generates an output signal that is sent to an encoder module.

12. The switch element of claim 10, where the frame data comparison is performed on a bit by bit or byte-by-byte basis.

13. The switch element of claim 10, wherein an action code routes a frame to a specified destination, discards a frame, sets a status for inspecting a frame or routes a frame based on a standard Fibre Channel addressing scheme.

14. The switch element of claim 10, wherein an alias cache entry includes prerequisite data to if a different entry'"'"'s compare results at a different fame word depth are to be used to determine an entry match.

21. The switch element of claim 10, wherein plural frame words are compared before any action is taken.

15. A method for routing and filtering frames using a fibre channel switch element having an alias cache, comprising:

determining if an incoming frame is pre-destined for a switch processor;

comparing incoming frame data to plural alias cache entries at the same time if the incoming frame is not pre-destined to the switch processor;

performing a word depth match by comparing incoming frame word depth with a programmed word depth; and

routing frames based on a programmed action code that is a part of an alias cache entry.

16. The method of claim 15, where the frame data comparison is performed on a bit by bit or byte-by-byte basis.

17. The method of claim 15, wherein an action code routes a frame to a specified destination, discards a frame, sets a status for inspecting a frame or routes a frame based on a standard Fibre Channel addressing scheme.

18. The method of claim 15, wherein an alias cache entry includes prerequisite data to determine if a different entry'"'"'s compare results at a different fame word depth are to be used to determine an entry match.

22. The method of claim 15, wherein plural frame words are compared before any action is taken.