← Back to Patent Explorer
US5521591A Expired / Lapsed US ⏱️ 0.0 years remaining

Switching networks with expansive and/or dispersive logical clusters for message routing

Assignee: Cisco Technology Inc
•
Filing: 1994-03-25
•
Granted: 1996-05-28
•
Expires: 2014-03-25
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A class of switching networks is comprised of expansive logical clusters and/or dispersive logical clusters. These clusters are of low degree. The class of networks include multibutterfly networks as well as multi-Benes networks. These networks provide for fault tolerance and routing and for efficient routing. Moreover, routing is provided in a non-blocking fashion.

Inventors

  • 👤 Sanjeev Arora
  • 👤 Thomas F. Knight, Jr.
  • 👤 Frank T. Leighton
  • 👤 Bruce M. Maggs
  • 👤 Eliezer Upfal

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 20:52
CPC Classifications
H; H04; H04L; H04L49/00; H04L49/45; H04L49/25; H04L49/15; H04L49/253; H04L49/254; H04L49/55; H04L49/557

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 173 words
A switching network for routing messages comprising at least one logical cluster which comprises: a) a first set of switches having N input switches for receiving messages and a second set of switches having approximately N output switches for outputting messages wherein the second set of switches is divided into at least two unique groups of switches; and b) connectors for connecting the first set of switches to the second set of switches wherein for every subset of input switches of size k of the first set of switches, there are at least x output switches in each group of the second set of switches that are connected to precisely one of the input switches of the subset of size k input switches, where k≦αN, x≦δαN, where k, x, and N are positive integers, N is equal to at least 8, where any particular subset includes any k of the N input switches, and where δ and α are positive constants less than one, such that the logical cluster exhibits a dispersion property.
Claim 2
Dependent Claim 173 words
A switching network for routing messages comprising at least one logical cluster which comprises: a) a first set of switches having N input switches for receiving messages and a second set of switches having approximately N output switches for outputting messages wherein the second set of switches is divided into at least two unique groups of switches; and b) connectors for connecting the first set of switches to the second set of switches wherein for every subset of input switches of size k of the first set of switches, there are at least x output switches in each group of the second set of switches that are connected to precisely one of the input switches of the subset of size k input switches, where k≦αN, x≦δαN, where k, x, and N are positive integers, N is equal to at least 8, where any particular subset includes any k of the N input switches, and where δ and α are positive constants less than one, such that the logical cluster exhibits a dispersion property.
Claim 3
Dependent Claim 29 words
A switching network as recited in claim 1 wherein the switching network is a multibutterfly switching network said multibutterfly switching network comprising a superposition of plural butterfly switching networks.
Claim 4
Dependent Claim 29 words
A switching network as recited in claim 1 wherein the switching network is a multi-Benes switching network, said multi-Benes switching network comprising a superposition of plural Benes switching networks.
Claim 5
Dependent Claim 86 words
A switching network as claimed in claim 1 comprised of a plurality of said logical clusters of switches that are interconnected by connections, each logical cluster further comprising controller means programmed to perform the following operations: declaring unusable switches as unavailable and, proceeding from an output level backward, declaring each switch unavailable if the switch does not have a sufficient quantity of connections to non-unavailable switches in each output group for each logical cluster, and avoiding switches declared unavailable in routing messages across the switching network.
Claim 6
Dependent Claim 17 words
A network as claimed in claim 4 wherein a busy switch or a faulty switch is unusable.
Claim 7
Dependent Claim 55 words
A network as claimed in claim 4 further comprising means for deactivating all switches in one of said logical clusters as well as all descendant switches connected to the outputs of said one of said logical clusters where a number of faulty input switches of that one of said logical clusters exceeds a predetermined threshold.
Claim 8
Dependent Claim 97 words
A network as claimed in claim 1 further comprising means for extending message paths between switches of the at least one logical cluster comprising: means for sending a proposal from a current switch for each message path that is to be extended to each neighbor switch in a desired direction of extension; means for returning an acceptance to the proposal to the current switch position from a neighbor switch if the neighbor receives exactly one proposal; and means for advancing each message path to include an accepting neighbor switch for each message path receiving exactly one acceptance.
Claim 9
Dependent Claim 42 words
A network as claimed in claim 7 further comprising means for sending placeholders on behalf of any message paths that are not moved forward such that the placeholders reserve a place at a switch to which the message path is to extend.
Claim 10
Dependent Claim 68 words
A switching network as claimed in claim 1 wherein the second set of switches is divided into at least two unique groups of switches and said at least one logical cluster exhibits an expansion property such that, for small subsets of k input switches, there are more than k switches in each unique group of the second set of switches connected to the subset of k input switches.
Claim 11
Dependent Claim 194 words
A switching network for routing messages comprising at least one logical cluster which comprises: a) at least an input set of switches for receiving messages and at least one set of switches after the input set of switches, including an output set of switches for outputting messages, the output set of switches being divided into at least two unique groups of switches, each switch in the input set of switches and in the at least one set of switches after the input set of switches making local routing decisions; and b) connectors for connecting the sets of switches wherein there exists for every subset of switches of size k in the input set of switches at least βk switches in each of said at least two unique groups of the output set of switches that can receive signals from the subset of k switches in the input set of switches, where β>1, where k is a positive integer, and k<αN for N equal to the total number of switches in the input set of switches, N being equal to at least 8, and for 2α<1, such that the logical cluster exhibits an expansion property.
Claim 12
Dependent Claim 194 words
A switching network for routing messages comprising at least one logical cluster which comprises: a) at least an input set of switches for receiving messages and at least one set of switches after the input set of switches, including an output set of switches for outputting messages, the output set of switches being divided into at least two unique groups of switches, each switch in the input set of switches and in the at least one set of switches after the input set of switches making local routing decisions; and b) connectors for connecting the sets of switches wherein there exists for every subset of switches of size k in the input set of switches at least βk switches in each of said at least two unique groups of the output set of switches that can receive signals from the subset of k switches in the input set of switches, where β>1, where k is a positive integer, and k<αN for N equal to the total number of switches in the input set of switches, N being equal to at least 8, and for 2α<1, such that the logical cluster exhibits an expansion property.
Claim 13
Dependent Claim 36 words
A switching network as recited in claim 10 wherein the switching network is a multibutterfly switching network comprising a plurality of said logical clusters, said multibutterfly switching network comprising a superposition of plural butterfly switching networks.
Claim 14
Dependent Claim 38 words
A switching network as recited in claim 10 wherein the switching network is a twin butterfly switching network comprising a plurality of said logical clusters, said twin butterfly switching network comprising a superposition of two butterfly switching networks.
Claim 15
Dependent Claim 36 words
A switching network as recited in claim 10 wherein the switching network is a multi-Benes switching network comprising a plurality of said logical clusters, said multi-Benes switching network comprising a superposition of plural Benes switching network.
Claim 16
Dependent Claim 14 words
A switching network as recited in claim 10 wherein α is at least 0.1.
Claim 17
Dependent Claim 15 words
A switching network as recited in claim 14 where α is approximately equal to 0.1.
Claim 18
Dependent Claim 38 words
A switching network as recited in claim 10 wherein each switch of the input set of switches and in the at least one set of switches after the input set of switches has two inputs and two outputs.
Claim 19
Dependent Claim 56 words
A switching network as claimed in claim 10 wherein said at least one logical cluster exhibits a dispersion property such that for every small subset of k switches in the input set of switches there are plural switches in the output set of switches, each having only one of the input set of switches connected thereto.
Claim 20
Dependent Claim 154 words
A switching network for routing messages comprising at least one logical cluster which comprises: an input set of switches equal in number to at least 8, having inputs for receiving messages and at least one set of switches after the input set of switches, including an output set of switches having outputs for outputting messages, wherein the output set of switches comprises at least two unique group of switches, each switch in the set of switches and in the at least one set of switches after the input set of switches making local routing decisions; and connectors for connecting switches in the logical cluster wherein for small subsets of size k of the input set of switches, there are more than k switches in each of said at least two unique groups of the output set of switches connected to the subsets of size k such that the logical cluster exhibits an expansion property.
Claim 21
Dependent Claim 154 words
A switching network for routing messages comprising at least one logical cluster which comprises: an input set of switches equal in number to at least 8, having inputs for receiving messages and at least one set of switches after the input set of switches, including an output set of switches having outputs for outputting messages, wherein the output set of switches comprises at least two unique group of switches, each switch in the set of switches and in the at least one set of switches after the input set of switches making local routing decisions; and connectors for connecting switches in the logical cluster wherein for small subsets of size k of the input set of switches, there are more than k switches in each of said at least two unique groups of the output set of switches connected to the subsets of size k such that the logical cluster exhibits an expansion property.
Claim 22
Dependent Claim 57 words
A switching network as recited in claim 18 wherein said at least one logical cluster exhibits a dispersion property such that for each of said small subsets of switches of the input set of switches there are plural switches in the output set of switches each having only one of the input set of switches connected thereto.

References Cited (Backward Citations)

US3851122A Cited
US4349702A Cited
US4651318A Cited
US4862161A Cited
EP0221360A2 Cited
EP0229299A2 Cited
US4731825A Cited
WO1989003566A2 Cited
EP0328854A1 Cited
US4845736A Cited
US5040173A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-05-28 1999-11-27 2000-05-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-05-28 2003-11-27 2004-05-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-05-28 2007-11-27 2008-05-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag