Automatic protection switching line card redundancy within an intermediate network node
AssigneeCisco Technology, Inc.
InventorsWilliam P. Brandt, Guy C. Fedorkow, Gary S. Muntz
Life of this patent
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Abstract
An apparatus and technique configures an intermediate network node, such as an aggregation router, to implement automatic protection switching (APS) redundancy among its line cards in the event of a failure to one of those cards. The APS line card redundancy provides redundancy among a pair of line cards connected to a performance routing engine of the router. Internal APS data paths are implemented in the router through the provision of an alias logic circuit that selects packet data from one of an adjacent pair of line cards and sends identical copies of data to that adjacent pair of line cards.
Claims45
A system adapted to configure an intermediate network node to implement redundancy among a pair of line cards of the node in the event of a failure to one of the line cards, the system comprising;
- a performance routing engine (PRE) of the node;
- data paths internal to the node, the internal data paths coupling the pair of line cards to the PRE;
- and
- an alias logic circuit configured to select data from one of the pair of line cards to the PRE, each line card of the pair of line cards having a different assigned slot number, the alias logic circuit selecting a first one of the different assigned slot numbers and associating the first slot number with data from both line cards of the pair of line cards, and the alias logic circuit further configured to send identical copies of data over the internal data paths to the pair of line cards.
A system adapted to configure an intermediate network node to implement redundancy among a pair of line cards of the node in the event of a failure to one of the line cards, the system comprising:
- a performance routing engine (PRE) of the node;
- data paths internal to the node, the internal data paths coupling the pair of line cards to the PRE;
- an alias logic circuit configured to select data from one of the pair of line cards to the PRE and further configured to send identical copies of data over the internal data paths to the pair of line cards, the alias logic circuit having control logic and a plurality of multiplexers coupled between buffers associated with clock domains and a memory of the node;
- a first multiplexer having a first input coupled to a first internal data path associated with an even numbered slot clock domain and a second input coup ed to a second internal data path associated with an odd numbered slot clock domain, the first multiplexer further having an output coupled to a second hardwired slot number port of a memory corresponding to the odd numbered slot clock domain;
- and
- a second multiplexer having a first input coupled to a first hardwired slot number port of the memory corresponding to the even numbered slot clock domain and a second input coupled to the second hardwired slot number port of the memory corresponding to the odd numbered slot clock domain, the second multiplexer further having an output coupled to the first internal data path associated with the even numbered slot clock domain.
A method for configuring a router to implement redundancy among a pair of line cards of the router in the event of a failure to one of the line cards, the method comprising the steps of:
- providing a performance routing engine (PRE) of the router;
- coupling the pair of line cards to the PRE by way of data paths internal to the router;
- selecting data from one of the pair of line cards for transmission to the PRE using an alias logic circuit, each line card of the pair of line cards having a different assigned slot number, the alias logic circuit selecting a first one of the different assigned slot numbers and associating the first slot number with data from both line cards of the pair of line cards;
- and
- sending identical copies of data over the internal data paths to the pair of line cards.
A method for configuring a router to implement redundancy among a pair of line cards of the router in the event of a failure to one of the line cards, the method comprising the steps of:
- providing a performance routing engine (PRE) of the router;
- coupling the pair of line cards to the PRE by way of data paths internal to the router;
- selecting data from one of the pair of line cards for transmission to the PRE using an alias logic circuit;
- sending identical copies of data over the internal data paths to the pair of line cards;
- providing a backplane of the router, the backplane having a plurality of slots, each slot comprising top and bottom subslots such that each slot is configured to accommodate one of a full-size line card and two half-sized line cards;
- binding two adjacent full-sized line cards into a redundant pair in accordance with a first redundancy mode;
- and
- combining a top subslot and a bottom subslot of a backplane slot to form one redundant interface in accordance with a second redundancy mode.
Apparatus for configuring an intermediate network node to implement redundancy among a pair of line cards of the node in the event of a failure to one of the line cards, the apparatus comprising:
- means for coupling the pair of line cards to a performance routing engine (PRE) of the node;
- means for selecting data from one of the pair of line cards for transmission to the PRE, each line card of the pair of line cards having a different assigned slot number, the alias logic circuit selecting a first one of the different assigned slot numbers and associating the first slot number with data from both line cards of the pair of line cards;
- and
- means for sending identical copies of data over the means for coupling to the pair of line cards.
Apparatus for configuring an intermediate network node to implement redundancy among a pair of line cards of the node in the event of a failure to one of the line cards, the intermediate network node including a backplane having a plurality of slots, each slot having top and bottom subslots such that each slot is configured to accommodate one of a full-size line card and two half-sized line cards, the apparatus comprising:
- means for coupling the pair of line cards to a performance routing engine (PRE) of the node;
- means for selecting data from one of the pair of line cards for transmission to the PRE;
- means for sending identical copies of data over the means for coupling to the pair of line cards;
- means for binding two adjacent full-sized line cards into a redundant pair;
- and
- means for combining a top subslot and a bottom subslot of a backplane slot to form one redundant interface of the node.
A computer readable medium containing executable program instructions for configuring an aggregation router to implement redundancy among a pair of line cards of the router in the event of a failure to one of the line cards, the executable program instructions comprising program instructions for:
- coupling the pair of line cards to a performance routing engine (PRE) of the router by way of data paths internal to the router;
- selecting data from one of the pair of line cards for transmission to the PRE using an alias logic circuit, each line card of the pair of line cards having a different assigned slot number, the alias logic circuit selecting a first one of the different assigned slot numbers and associating the first slot number with data from both line cards of the pair of line cards;
- and
- sending identical copies of data over the internal data paths to the pair of line cards.
A computer readable medium containing executable program instructions for configuring a router to implement redundancy among a pair of line cards of the router in the event of a failure to one of the line cards, the router includes a backplane having a plurality of slots, each slot comprising top and bottom subslots such that each slot is configured to accommodate one of a full-size line card and two half-sized line cards, the executable program instructions comprising program instructions for:
- coupling the pair of line cards to a performance routing engine (PRE) of the router by way of data paths internal to the router;
- selecting data from one of the pair of line cards for transmission to the PRE using an alias logic circuit;
- sending identical copies of data over the internal data paths to the pair of line cards;
- binding two adjacent full-sized line cards into a redundant pair in accordance with a first redundancy mode;
- and
- combining a top subslot and a bottom subslot of a backplane slot to form one redundant interface in accordance with a second redundancy mode.
A system for operating a network node, the system comprising:
- a forwarding engine of the network node;
- and
- an alias logic circuit configured to select data from either a first or a second line card of the pair of line cards, the alias logic circuit associating a first slot number value with the data from the first and the second line cards, whereby the forwarding engine perceives the data from either the first or the second line card to be sourced from the first line card.
A method for operating a network node, the method comprising the steps of:
- providing a forwarding engine of the network node;
- and
- selecting data from either a first or a second line card of the pair of line cards;
- associating a first slot number value with the data from the first and the second line cards, whereby the forwarding engine perceives the data from either the first or the second line card to be sourced from the first line card.
A computer readable medium containing executable program instructions for execution on a processor, the executable program instructions comprising program instructions for:
- selecting data from either a first or a second line card of the pair of line cards;
- associated a first slot number value with the data from the first and the second line cards, whereby a forwarding engine perceives the data from either the first or the second line card to be sourced from the first line card.
A system for implementing redundancy in a network node, the system comprising:
- a forwarding engine of the network node;
- a first line card associated with a first slot number;
- a second line card associated with a second slot number;
- and
- an alias logic circuit configured to receive data from the first and the second line cards of the redundant pair, the alias logic circuit fiber configured to associate data from the first line card with the first slot number and data from the second line card with the first slot number, such that the forwarding engine will perceive the data from either the first or the second line card as sourced from the first line card.
A method for implementing redundancy in a network node, the method comprising the steps of:
- providing a forwarding engine of the network node;
- associating a first line card with a first slot number;
- associating a second line card with a second slot number;
- associating data from the first line card with the first slot number;
- and
- associating data from the second line card with the first slot number, such that the forwarding engine will perceive the data from either the first or the second line card as sourced from the first line card.
A system for implementing redundancy in a network node, the system comprising:
- means for associating a first line card with a first slot number;
- means for associating a second line card with a second slot number,
- means for associating data from the first line card with the first slot number;
- and
- means for associating data from the second line card with the first slot number,
- such that a forwarding engine will perceive the data from either the first or the second line card as sourced from the first line card.
A computer readable medium containing executable program instructions for implementing redundancy in a network node, the executable program instructions comprising program instructions for:
- associating a first line card with a first slot number;
- associating a second line card with a second slot number,
- associating data from the first line card with the first slot number;
- and
- associating data from the second line card with the first slot number, such that a forwarding engine will perceive the data from either the first or the second line card as sourced from the first line card.
Dependencies are inferred from the claim text.