US6115378A
Expired / Lapsed
US
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Multi-layer distributed network element
Assignee: Oracle America Inc
•
Filing: 1997-06-30
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Granted: 2000-09-05
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Expires: 2017-06-30
Abstract
Abstract A distributed multi-layer network element delivering Layer 2 (data link layer) wire-speed performance within and across subnetworks, allowing queuing decisions to be based on Layer 3 (network layer) protocol and endstation information combined with Layer 2 topology information. The network element performs packet relay functions using multiple switching subsystems as building blocks coupled to each other to form a larger switch that acts as both a router and a bridge. Each switching subsystem includes a hardware forwarding search engine having a switching element coupled to a forwarding memory and an associated memory. The switching subsystems and their fully meshed interconnection allow the network element to scale easily without compromising packet forwarding speed and without significantly increasing the storage requirements of each forwarding memory.
Inventors
- 👤 Ariel Hendel
- 👤 Shimon Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:09
CPC Classifications
H; H04; H04L; H04L45/00; H04L45/54; H04L45/66; H04L45/74; H04L45/745; H04L49/00; H04L49/60; H04L49/602; H04L49/20; H04L49/205; H04L49/35; H04L49/351; H04L49/354
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
151 words
In a network element for receiving and forwarding packets between nodes, the network element having separate first and second subsystem circuitry coupled by an internal link, the subsystems having first and second forwarding memories, respectively, a method for relaying packets comprising the steps of: receiving a packet by the first subsystem circuitry the packet having a first header portion including a destination address; searching the first forwarding memory for a first entry that matches the destination address in the first header portion; sending the packet to the second subsystem circuitry through the internal link in response to the first entry matching the destination address in the first header portion and without changing the destination address of the packet; and forwarding the packet to a destination specified in the first header portion in response to the first header portion including the destination address matching a second entry in the second forwarding memory.
Claim 2
Dependent Claim
151 words
In a network element for receiving and forwarding packets between nodes, the network element having separate first and second subsystem circuitry coupled by an internal link, the subsystems having first and second forwarding memories, respectively, a method for relaying packets comprising the steps of: receiving a packet by the first subsystem circuitry the packet having a first header portion including a destination address; searching the first forwarding memory for a first entry that matches the destination address in the first header portion; sending the packet to the second subsystem circuitry through the internal link in response to the first entry matching the destination address in the first header portion and without changing the destination address of the packet; and forwarding the packet to a destination specified in the first header portion in response to the first header portion including the destination address matching a second entry in the second forwarding memory.
Claim 3
Dependent Claim
16 words
A method as in claim 1 wherein the destination address is a Layer 2 destination address.
Claim 4
Dependent Claim
39 words
A method as in claim 1 wherein the first entry comprises a Layer 2 address that was learned by the second subsystem and copied to the first forwarding memory prior to the packet being received by the first subsystem.
Claim 5
Dependent Claim
32 words
A method as in claim 1 wherein the second entry comprises a Layer 2 address that was learned by the second subsystem prior to the packet being received by the first subsystem.
Claim 6
Dependent Claim
151 words
In a network element for receiving and forwarding packets between nodes, the network element having first and second subsystems coupled by an internal link, the subsystems having first and second forwarding memories, respectively, a method for relaying packets comprising the steps of: receiving a packet by the first subsystem, the packet having a second header portion, the second header portion including a network layer destination address; searching the first forward memory for a type 2 entry that matches the second header portion; sending the packet and a control signal to the second subsystem through the internal link in response to the type 2 entry matching the first header portion, the control signal being associated with the type 2 entry and defining a queuing priority; and forwarding the packet from the second subsystem, according to said queuing priority set by the control signal, to a destination specified in the second header portion.
Claim 7
Dependent Claim
151 words
In a network element for receiving and forwarding packets between nodes, the network element having first and second subsystems coupled by an internal link, the subsystems having first and second forwarding memories, respectively, a method for relaying packets comprising the steps of: receiving a packet by the first subsystem, the packet having a second header portion, the second header portion including a network layer destination address; searching the first forward memory for a type 2 entry that matches the second header portion; sending the packet and a control signal to the second subsystem through the internal link in response to the type 2 entry matching the first header portion, the control signal being associated with the type 2 entry and defining a queuing priority; and forwarding the packet from the second subsystem, according to said queuing priority set by the control signal, to a destination specified in the second header portion.
Claim 8
Dependent Claim
68 words
A method as in claim 5 wherein the step of sending the packet and a control signal further includes sending a second control signal which identifies the packet as a member of a flow to the second subsystem, and further comprising the step of searching the second forwarding memory for a type 2 entry that matches the second header portion in response to receiving the second control signal.
Claim 9
Dependent Claim
171 words
A network element for interconnecting nodes, comprising: first subsystem circuitry having a first forwarding memory and configured to search the first forwarding memory for a first entry that matches a destination address in a first header portion of a packet; second subsystem circuitry separate from the first subsystem circuitry and having a second forwarding memory; and an internal link coupling the first and second subsystems for passing packets and control information from the first subsystem circuitry to the second subsystem circuitry, wherein the first subsystem circuitry is configured to send the packet to the second subsystem circuitry through the internal link in response to the first entry matching the first header portion including the destination address, and without changing a Layer 2 destination address of the packet, and wherein the second subsystem circuitry is configured to forward the packet to a destination specified in the first header portion in response to a second entry in the second forwarding memory matching the destination address in the first header portion of the packet.
Claim 10
Dependent Claim
171 words
A network element for interconnecting nodes, comprising: first subsystem circuitry having a first forwarding memory and configured to search the first forwarding memory for a first entry that matches a destination address in a first header portion of a packet; second subsystem circuitry separate from the first subsystem circuitry and having a second forwarding memory; and an internal link coupling the first and second subsystems for passing packets and control information from the first subsystem circuitry to the second subsystem circuitry, wherein the first subsystem circuitry is configured to send the packet to the second subsystem circuitry through the internal link in response to the first entry matching the first header portion including the destination address, and without changing a Layer 2 destination address of the packet, and wherein the second subsystem circuitry is configured to forward the packet to a destination specified in the first header portion in response to a second entry in the second forwarding memory matching the destination address in the first header portion of the packet.
Claim 11
Dependent Claim
17 words
A network element as in claim 7 wherein the destination address is a Layer 2 destination address.
Claim 12
Dependent Claim
39 words
A network element as in claim 7 wherein the first entry comprises a Layer 2 address that was learned by the second subsystem and copied to the first entry prior to the packet being received by the first subsystem.
Claim 13
Dependent Claim
33 words
A network element as in claim 9 wherein the second entry comprises a Layer 2 address that was learned by the second subsystem prior to the packet being received by the first subsystem.
Claim 14
Dependent Claim
62 words
A network element as in claim 7 further comprising a central processing system (CPS) having a central memory (CM), the CPS coupled to each subsystem and configured to cause a source address learned by the second subsystem to be stored in an entry of the first forwarding memory in response to finding a copy of the source address in the central memory.
Claim 15
Dependent Claim
55 words
A network element as in claim 7 wherein the first subsystem further comprises a first associated memory and an internal port coupling the internal link, the first associated memory for storing a port value identifying the internal port, the first subsystem configured to associate the port value with the first entry in the forwarding memory.
Claim 16
Dependent Claim
41 words
A network element as in claim 7 wherein the first subsystem is further configured to flood the packet to a predefined subnet in response to no entry in the first forwarding memory matching the destination address in the first header portion.
Claim 17
Dependent Claim
82 words
A network element as in claim 7 wherein the first subsystem is further configured to send the packet to the second subsystem in response to a second entry in the first forwarding memory matching a second header portion of the packet, the second header portion comprising a network layer destination address separate from the destination address in the first portion header, and wherein the second subsystem is further configured to forward the packet to a destination specified in the second header portion.
Claim 18
Dependent Claim
46 words
A network element as in claim 14 wherein the second subsystem is further configured to forward the packet to a destination specified in the second header portion in response to a fourth entry in the second forwarding memory matching the second header portion of the packet.
Claim 19
Dependent Claim
49 words
A network element as in claim 14 wherein the third subsystem is further configured to perform a search of the second forwarding memory for an entry matching the second header portion of the packet in response to receiving the packet and a first control signal from the first subsystem.
Claim 20
Dependent Claim
43 words
A network element as in claim 14 wherein the second subsystem is configured to forward the packet in accordance with quality of service (QOS) information received from the first subsystem, the QOS information being associated with the third entry in the first subsystem.
Claim 21
Dependent Claim
35 words
A network element as in claim 15 wherein the second subsystem is further configured to associate second QOS information with the fourth entry, the second QOS information overriding QOS information received from the first subsystem.
Claim 22
Dependent Claim
95 words
A network element as in claim 7 further comprising a central processing system (CPS) having a central memory (CM), the CPS coupled to each subsystem and configured with a copy of all source addresses learned by the first and second subsystems, and configured to cause a source address learned by the second subsystem to be stored in an entry of the first forwarding memory in response to a notification from the first subsystem that a destination address of a packet does not match any entry in the first forwarding memory but matches said source address.
Claim 23
Dependent Claim
98 words
A method as in claim 5 wherein the network element further comprises: a central processing system (CPS) having a central memory (CM), the CPS coupled to each subsystem and configured with a copy of all source addressed learned by the first and second subsystems, and configured to cause a source address learned by the second subsystem to be stored in an entry of the first forwarding memory in response to a notification from the first subsystem that a destination address of a packet does not match any entry in the first forwarding memory but matches said source address.
Claim 24
Dependent Claim
64 words
A method as in claim 6 wherein a flow priority is associated with the type 2 entry in the second subsystem, and wherein the step of forwarding the packet from the second subsystem is in response to the type 2 entry matching the second header portion, the packet being forwarded from the second subsystem according to the flow priority rather than the queuing priority.
Claim 25
Dependent Claim
92 words
A network element as in claim 7 wherein each subsystem has a plurality of external ports and at least one internal port, the internal port connects to the internal link and the external ports connect to other nodes, and wherein the packet arriving through one of the external ports in the first subsystem and whose destination address in the first header portion does not match any entry in the first forwarding memory is flooded to all of the external ports, except the port of arrival, and the at least one internal port.
Claim 26
Dependent Claim
18 words
A network element as in claim 7 wherein each subsystem is implemented as part of a separate IC.
Claim 27
Dependent Claim
168 words
A network element for interconnecting nodes, comprising: first subsystem having a first forwarding memory and configured to search the first forwarding memory for a first entry that matches a first header portion of a packet; second subsystem having a second forwarding memory; an internal link coupling the first and second subsystems for passing packets and control information from the first subsystem to the second subsystem; and a central processing system (CPS) having a central memory (CM), the CPS coupled to each subsystem and configured to cause a source address learned by the second subsystem to be stored in an entry of the first forwarding memory in response to finding a copy of the source address in the central memory, and wherein the first subsystem is configured to send the packet to the second subsystem through the internal link in response to the first entry matching the first header portion, and the second subsystem is configured to forward the packet to a destination specified in the first header portion.
Claim 28
Dependent Claim
168 words
A network element for interconnecting nodes, comprising: first subsystem having a first forwarding memory and configured to search the first forwarding memory for a first entry that matches a first header portion of a packet; second subsystem having a second forwarding memory; an internal link coupling the first and second subsystems for passing packets and control information from the first subsystem to the second subsystem; and a central processing system (CPS) having a central memory (CM), the CPS coupled to each subsystem and configured to cause a source address learned by the second subsystem to be stored in an entry of the first forwarding memory in response to finding a copy of the source address in the central memory, and wherein the first subsystem is configured to send the packet to the second subsystem through the internal link in response to the first entry matching the first header portion, and the second subsystem is configured to forward the packet to a destination specified in the first header portion.
Claim 29
Dependent Claim
196 words
A network element for interconnecting nodes, comprising: first subsystem having a first forwarding memory and configured to search the first forwarding memory for at least one of a first entry that matches a first header portion of a packet and a third entry that matches a second header portion of the packet, the second header portion comprising a network layer destination address; second subsystem having a second forwarding memory; and an internal link coupling the first and second subsystems for passing packets and control information from the first subsystem to the second subsystem, wherein the first subsystem is configured to send the packet to the second subsystem through the internal link in response to the first entry matching the first header portion, the second subsystem is configured to forward the packet to at least one of a destination specified in the first header portion, and a destination specified in the second header portion, and wherein the second subsystem is further configured to perform a search of the second forwarding memory for an entry matching the second header portion of the packet in response to receiving the packet and a first control signal from the first subsystem.
Claim 30
Dependent Claim
196 words
A network element for interconnecting nodes, comprising: first subsystem having a first forwarding memory and configured to search the first forwarding memory for at least one of a first entry that matches a first header portion of a packet and a third entry that matches a second header portion of the packet, the second header portion comprising a network layer destination address; second subsystem having a second forwarding memory; and an internal link coupling the first and second subsystems for passing packets and control information from the first subsystem to the second subsystem, wherein the first subsystem is configured to send the packet to the second subsystem through the internal link in response to the first entry matching the first header portion, the second subsystem is configured to forward the packet to at least one of a destination specified in the first header portion, and a destination specified in the second header portion, and wherein the second subsystem is further configured to perform a search of the second forwarding memory for an entry matching the second header portion of the packet in response to receiving the packet and a first control signal from the first subsystem.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-09-05 | 2004-03-06 | 2004-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-09-05 | 2008-03-06 | 2008-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-09-05 | 2012-03-06 | 2012-09-05 | $7700.00 | Window Closed / Lapsed |