Route lookup caching for a fiber channel switch
AssigneeMcData Corporation
InventorsWilliam J. Mitchem, John Retta
Life of this patent
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Abstract
A route caching design in a fiber channel switch for providing quick access to recently used D_ID and exit port combinations. The fiber channel switch has a plurality of ports, each are coupled to a central route look-up table. A cache is coupled to each port for storing D_ID to exit port association information received from the central route look-up table.
Claims28
A method for routing a data frame through a fibre channel fabric, said fibre channel fabric comprising a first switch having a plurality of ports, said ports are operative for transmitting and receiving said data frame, said method comprising:
- supplying a data frame to a selected port, wherein the data frame has an associated destination identification;
- providing a plurality of route caches, at least one route cache coupled to said selected port;
- creating an association between an exit port and a destination identification;
- storing said association in said at least one route cache;
- and using the selected port, transferring the supplied data frame from the selected port to the exit port.
A method for storing a data frame route relationship in a fibre channel fabric, said method comprising:
- providing a cache operatively coupled to a port of a first fibre channel switch;
- creating said data frame route relationship by associating an exit port of said fibre channel switch with a destination identification, wherein said destination identification is associated with a data frame and represents a destination location for transmitting said data frame;
- storing said association in said data cache while the data frame resides in the port.
A method for retrieving an association stored in a data cache in a fiber channel fabric, said method comprising:
- at a fibre channel switching port, requesting an exit port from a route control module based on a destination identification;
- at said route control module, querying said data cache for an exit port associated with said destination identification;
- and
- returning said exit port associated with said destination identification from said route control module to said fibre channel switching port if said destination identification is found in said data cache.
A fibre channel fabric having reduced latency and increased through put capacity comprising:
- a switch having a plurality of ports embodied thereon for transmitting and receiving data frames;
- a route control module coupled to at least one of said ports, said route control module for providing an identification of an exit port in response to a request from said port for said exit port, said request comprising a destination identification;
- and
- a cache coupled to said route control module for storing an association between said exit port and said destination identification.
A fibre channel switch comprising:
- a plurality of ports;
- a central route look-up table;
- and
- a cache coupled to each port for storing information from said central route look-up table.
A fibre channel port comprising:
- an interface to a central route look-up table;
- a cache for holding information from said route look-up table;
- and
- an interface for receiving a data frame and a destination identification associated with said frame.
Dependencies are inferred from the claim text.