US5802333A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Network inter-product stacking mechanism in which stacked products appear to the network as a single device
Assignee: Hewlett Packard Enterprise Development LP
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Filing: 1997-01-22
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Granted: 1998-09-01
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Expires: 2017-01-22
Abstract
Abstract A combination of a standardized high speed switch interconnect scheme and global management makes a stack of multiple switches appear as one large managed high speed switch without impeding the transmission of information between individual switches within the managed switch, thereby providing a high speed connection between networking devices. Standard two port PCI bridges are interconnected such that an apparent three port bridge is created. This allows a transaction between systems to occur without interrupting intermediate systems. By logically connecting the PCI bus of one system to that of another, a processor in one system is allowed to access all devices in all the systems that are connected in the stack. In this way only one processor or management entity is required to configure and control a group of stacked systems.
Inventors
- 👤 Bruce W. Melvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:37
CPC Classifications
H; H04; H04L; H04L49/00; H04L49/35; H04L49/351
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
90 words
An apparatus for high speed interconnection of devices on an electronic network, comprising: a plurality of switches, wherein each switch incorporates two bridges; an interconnect bus for interconnecting each switch via a first of said bridges; and a local bus associated with each switch, wherein said local bus is isolated from said interconnect bus via a second of said bridges; wherein said switches are interconnected as a stack of switches that appear to said network as one switch without impeding the transmission of information between individual switches within said stack.
Claim 2
Independent Claim
90 words
An apparatus for high speed interconnection of devices on an electronic network, comprising: a plurality of switches, wherein each switch incorporates two bridges; an interconnect bus for interconnecting each switch via a first of said bridges; and a local bus associated with each switch, wherein said local bus is isolated from said interconnect bus via a second of said bridges; wherein said switches are interconnected as a stack of switches that appear to said network as one switch without impeding the transmission of information between individual switches within said stack.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1, wherein said first bridge allows communication through any switch without affecting said switch's local bus.
Claim 4
Dependent Claim
14 words
The apparatus of claim 1, wherein said interconnect bus further comprises: an external cable.
Claim 5
Dependent Claim
13 words
The apparatus of claim 1, wherein said local bus is a PCI bus.
Claim 6
Dependent Claim
16 words
The apparatus of claim 1, further comprising: a second local bus interposed between said two bridges.
Claim 7
Dependent Claim
21 words
The apparatus of claim 5, wherein said two bridges further comprise: a PCI-to-PCI bridge that transparently interconnects said two local buses.
Claim 8
Dependent Claim
25 words
The apparatus of claim 1, wherein each of said bridges decodes each transaction to determine if access is aimed at a device across said bridge.
Claim 9
Dependent Claim
40 words
The apparatus of claim 7, wherein said bridge determines that an access is aimed at a target device across said bridge, said bridge holds off an initiator, and said bridge gains access to a local bus associated with said bridge.
Claim 10
Dependent Claim
35 words
The apparatus of claim 8, wherein said target device signals said bridges when it is ready to accept a transfer and said bridges, in turn, signal said initiator that the transaction is able to proceed.
Claim 11
Dependent Claim
12 words
The apparatus of claim 8, further comprising: a plurality of chained bridges.
Claim 12
Dependent Claim
16 words
The apparatus of claim 1, wherein a specific device number is assigned to a given switch.
Claim 13
Dependent Claim
21 words
The apparatus of claim 11, wherein said device number is assigned corresponding to the position of the switch in said stack.
Claim 14
Dependent Claim
67 words
The apparatus of claim 1, wherein each switch in said stack uses a plurality of device numbers, a last device number used is conveyed to a next switch, said next switch assigns device numbers consecutively, starting with the last device number used in a previous switch in said stack, and said next switch sends the last device number used to a further next switch in said stack.
Claim 15
Dependent Claim
23 words
The apparatus of claim 1, wherein all transactions are relative to a system clock, and wherein all buses are synchronous with each other.
Claim 16
Dependent Claim
21 words
The apparatus of claim 14, wherein said bridges at each switch further comprise: individual clocks for both primary and secondary ports.
Claim 17
Dependent Claim
18 words
The apparatus of claim 15, wherein skew between said individual clocks is compensated for by said bridge itself.
Claim 18
Dependent Claim
20 words
The apparatus of claim 1, wherein one switch provides a master clock source for all other switches in said stack.
Claim 19
Dependent Claim
24 words
The apparatus of claim 17, wherein all other switches in said stack disable their internal clocks and use a form of said master clock.
Claim 20
Dependent Claim
27 words
The apparatus of claim 17, wherein said clock sent to each switch is a delayed version of the clock delivered to a previous switch in said stack.
Claim 21
Dependent Claim
27 words
The apparatus of claim 1, wherein a specific device number is reassigned to a given switch when a switch is added to or removed from said stack.
Claim 22
Dependent Claim
21 words
The apparatus of claim 1, wherein a single management entity is used to configure and control a group of stacked switches.
Claim 23
Dependent Claim
17 words
The apparatus of claim 1, wherein said switches are interconnected to allow concurrent accesses between said switches.
Claim 24
Dependent Claim
18 words
The apparatus of claim 1, further comprising: a management stacking card that provides management for the entire stack.
Claim 25
Dependent Claim
96 words
A switch for high speed interconnection of a plurality of devices on an electronic network, comprising: at least two bridges; and a first external connector for interconnecting one bridge of said switch to another switch via an interconnecting bus; and a local bus associated with said switch, wherein said local bus is isolated from said first external connector via a second of said bridges; wherein said switch is adapted for interconnection in a stack of switches that appear to said network as one switch without impeding the transmission of information between individual switches within said stack.
Claim 26
Dependent Claim
96 words
A switch for high speed interconnection of a plurality of devices on an electronic network, comprising: at least two bridges; and a first external connector for interconnecting one bridge of said switch to another switch via an interconnecting bus; and a local bus associated with said switch, wherein said local bus is isolated from said first external connector via a second of said bridges; wherein said switch is adapted for interconnection in a stack of switches that appear to said network as one switch without impeding the transmission of information between individual switches within said stack.
Claim 27
Dependent Claim
96 words
A process for high speed interconnection of devices on an electronic network, comprising the steps of: providing a plurality of switches, wherein each switch incorporates two bridges; providing an interconnect bus for interconnecting each switch via a first of said bridges; and providing a local bus associated with each switch, wherein said local bus is isolated from said interconnect bus via a second of said bridges; wherein said switches are interconnected as a stack of switches that appear to said network as one switch without impeding the transmission of information between individual switches within said stack.
Claim 28
Dependent Claim
96 words
A process for high speed interconnection of devices on an electronic network, comprising the steps of: providing a plurality of switches, wherein each switch incorporates two bridges; providing an interconnect bus for interconnecting each switch via a first of said bridges; and providing a local bus associated with each switch, wherein said local bus is isolated from said interconnect bus via a second of said bridges; wherein said switches are interconnected as a stack of switches that appear to said network as one switch without impeding the transmission of information between individual switches within said stack.
Claim 29
Dependent Claim
20 words
The process of claim 25, wherein said first bridge allows communication through any switch without affecting said switch's local bus.
Claim 30
Dependent Claim
20 words
The process of claim 25, further comprising the step of: providing a second local bus interposed between said two bridges.
Claim 31
Dependent Claim
16 words
The process of claim 27, further comprising the step of: transparently interconnecting said two local buses.
Claim 32
Dependent Claim
28 words
The process of claim 25, further comprising the step of: decoding each transaction at said switch to determine if access is aimed at a device across said bridge.
Claim 33
Dependent Claim
38 words
The process of claim 29, further comprising the steps of: determining that an access is aimed at a target device across said bridge; holding off an initiator; and gaining access to a local bus associated with said bridge.
Claim 34
Dependent Claim
32 words
The process of claim 30, further comprising the steps of: signaling said bridge when it is ready to accept a transfer; and signaling said initiator that the transaction is able to proceed.
Claim 35
Dependent Claim
20 words
The process of claim 25, further comprising the step of: assigning a specific device number to a given switching component.
Claim 36
Dependent Claim
21 words
The process of claim 32, wherein said device numbers are assigned corresponding to the position of the switch in said stack.
Claim 37
Dependent Claim
28 words
The process of claim 33, wherein a switch at the top of said stack has a lower device number than a switch at the bottom of said stack.
Claim 38
Dependent Claim
17 words
The process of claim 32, wherein each switch in said stack uses a plurality of device numbers.
Claim 39
Dependent Claim
53 words
The process of claim 35, further comprising the steps of: conveying a last device number used to a next switch; assigning device numbers consecutively, starting with the last device number used in a previous switch in said stack; and sending the last device number used to a further next switch in said stack.
Claim 40
Dependent Claim
23 words
The process of claim 25, wherein all transactions are relative to a system clock, and wherein all buses are synchronous with each other.
Claim 41
Dependent Claim
19 words
The process of claim 25, further comprising the step of: compensating for skew between individual clocks at each switch.
Claim 42
Dependent Claim
24 words
The process of claim 25, further comprising the step of: providing a single management entity to configure and control a group of stacked switches.
Claim 43
Dependent Claim
25 words
The process of claim 25, further comprising the step of: providing a plurality of switches that are interconnected to allow concurrent access between said switches.
Claim 44
Dependent Claim
22 words
The process of claim 25, further comprising the step of: providing a management stacking card that provides management for the entire stack.
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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) | 2001-08-31 | 2002-03-02 | 2002-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-31 | 2006-03-02 | 2006-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-31 | 2010-03-02 | 2010-09-01 | $7700.00 | Window Closed / Lapsed |