Two-Stage Switch

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Two-Stage Switch
High-Performance Networking Group Isaac
Keslassy, Nick McKeown
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Input-Queued Packet Switch
Crossbar
1
. . . .
N
1
N
. . . .
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Round-Robin Scheduling

• Uniform non-bursty traffic gt 100 throughput
• Problem traffic is non-uniform bursty

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Two-Stage Switch (I)
External Outputs
Internal Inputs
External Inputs
First Round-Robin
Second Round-Robin
C.S.Chang et al. http//www.ee.nthu.edu.tw/csch
ang/PartI.pdf
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Two-Stage Switch (I)
External Outputs
Internal Inputs
External Inputs
First Round-Robin
Second Round-Robin
C.S.Chang et al. http//www.ee.nthu.edu.tw/csch
ang/PartI.pdf
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Two-Stage Switch (I)
External Outputs
Internal Inputs
External Inputs
First Round-Robin
Second Round-Robin

• No scheduling
• Problem unbounded mis-sequencing

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Two-Stage Switch (II)
New
N3 instead of N2
Infocom02 paper http//klamath.stanford.edu/ke
slassy/tmp/two-stage.pdf
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Current Work

• Practical implementation of this scheme
• Statistical bounds on mis-sequencing
• Queue length distributions
• TCP properties

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An optical two-stage switch
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Phase 2
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