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US 7,583,674 B2Granted
Switch and method for supporting internet protocol (IP) network tunnels
AssigneeAlcatel Lucent
InventorGregory G. Page
Life of this patent
Estimating the term…
Abstract
A switch and a method are described herein that are capable of supporting a “new” IP network tunnel even though the switch has an “old” application specific integrated circuit (ASIC) that did not originally support the routing of a packet with the “new” tunnel type (i.e., the “new” tunnel type was developed and implemented after the design of the “old” ASIC).
Claims13
A switch, comprising:
- an application specific integrated circuit (ASIC);
- and
- a central processing unit (CPU), where said ASIC receives a first formatted packet, performs a first table lookup using a destination address in the first formatted packet, revises the first formatted packet to be a second formatted packet which has a special destination address added thereto and routes the second formatted packet to said CPU which recognizes that the second formatted packet is to be a tunneled packet and performs a second table lookup using at least a portion of the special destination address and revises the second formatted packet to be a third formatted packet which is the tunneled packet that is subsequently outputted from a specific tunnel interface on a specific egress path.
A method for routing a packet at a switch which includes an application specific integrated circuit (ASIC) and a central processing unit (CPU), said method comprising the steps of:
- said ASIC performs the following steps:
- receiving a first formatted packet;
- performing a first table lookup using a destination address located in the first formatted packet to obtain a special destination address;
- revising said the first formatted packet to be a second formatted packet which has the special destination address added thereto;
- and
- routing the second formatted packet;
- and
- said CPU performs the following steps:
- receiving the second formatted packet;
- recognizing that the second formatted packet is to be a tunneled packet;
- performing a second table lookup using at least a portion of the special destination address to obtain header information;
- revising the second formatted packet to be a third formatted packet which has the header information added thereto;
- and
- routing the third formatted packet;
- and
- said ASIC performs the following steps:
- receiving the third formatted packet;
- and
- outputting the third formatted packet from a specific tunnel interface on a specific egress path.
16 more elements
A switch, comprising:
- an application specific integrated circuit (ASIC) which includes:
- a port that receives a first formatted packet;
- and
- an IP routing logic unit that receives the first formatted packet and performs a first table lookup using a destination address in the first formatted packet to obtain a special destination address and then revises the first formatted packet to be a second formatted packet which has the special destination address added thereto and then routes the second formatted packet;
- and
- a central processing unit (CPU) which includes:
- a device driver that receives the second formatted packet and recognizes that the second formatted packet is to be a tunneled packet;
- and
- a fast path handler that performs a second table lookup using at least a portion of the special destination address therein to obtain header information and then revises the second formatted packet to be a third formatted packet which has the header information added thereto and then routes the third formatted packet;
- and
- said ASIC further includes:
- an egress packet logic unit that receives the third formatted packet and routes the third formatted packet;
- and
- said port receives the third formatted packet and outputs the third formatted packet which is a tunneled packet from a specific tunnel interface on a specific egress path.
11 more elements
A switch, comprising:
- a first application specific integrated circuit (ASIC) which includes:
- a port that receives a first formatted packet;
- and
- an IP routing logic unit that receives the first formatted packet and performs a first table lookup using a destination address in the first formatted packet to obtain a special destination address and then revises the first formatted packet to be a second formatted packet which has the special destination address added thereto and then routes the second formatted packet;
- and
- a second ASIC which includes:
- a fast path handler that receives the second formatted packet and recognizes that the second formatted packet is to be a tunneled packet and performs a second table lookup using at least a portion of the special destination address therein to obtain header information and then revises the second formatted packet to be a third formatted packet which has the header information added thereto and then routes the third formatted packet;
- and
- said first ASIC further includes:
- an egress packet logic unit that receives the third formatted packet and routes the third formatted packet;
- and
- said port receives the third formatted packet and outputs the third formatted packet which is a tunneled packet from a specific tunnel interface on a specific egress path.
9 more elements
Dependencies are inferred from the claim text.