A Study Of Cyclone Technology

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A Study Of Cyclone Technology
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Table of Content

• Overview
• Contributions
• The need for time-based resource management
• Cyclone technology - basic idea
• Description of a Cyclone network
• Clock synchronization
• Data movements
• Connection management
• Scheduling
• Adaptation layer
• Fault handling
• Performance
• Advantages and limitations
• Open issues

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Overview

• Current networking
• event-based, on-demand resource allocation
• best effort performance
• New classes of traffic placing stringent
  requirements on the communications
• Time-based resource management in a synchronous
  manner
• End-to-end coordination among network components
• no congestion, loss, jitter
• better utilization of bandwidth
• one byte header
• reduced control messages
• reduced routing information
• well-suited network environment for traffic with
  stringent timing requirements

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Contributions

• Time-based networking technology
• components
• protocols
• operations
• host interface
• Time-based resource management
• Alternate way of managing resources in networking
• without requiring very accurate and highly
  synchronized clocks
• without consuming significant amount of bandwidth
  for handling timing variability

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Time-based Resource Management In Networking
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Cyclone Technology - Basic Idea
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Data Movements - Basic
Free slot list
Incoming link
Outgoing link
Slot buffer
Pointer buffer
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Data Movements
switch
controller
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Types Of Traffic Supported

• Connection-oriented
• Scheduled traffic
• data available at known time instant (temporal
  profile)
• resources reserved when establishing a connection
• On-demand traffic
• source routing
• dynamic resource allocation
• possible loss of a chunk

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Description Of Cyclone Network

• Chunk
• Slot and slot time
• Time tag
• Period
• Fixed design parameters
• the size of a chunk
• the duration of a period

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Chunk Types

• Three types - Control/Scheduled/On-demand
• Control chunk
• multiple sub-chunks in a chunk
• connection request chunk
• confirm/reject/abort/terminate chunk
• pathfinder chunk
• Scheduled chunk
• scheduled traffic data chunk
• scheduled traffic data acknowledgement/retransmiss
  ion request chunk
• On-demand chunk
• on-demand traffic data chunk
• on-demand traffic data acknowledgement/retransmiss
  ion request chunk

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Multiple Sub-chunks In A Chunk
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Connection Request Chunk
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Confirm/Reject/Abort/Terminate Chunk
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Pathfinder Chunk
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Scheduled Traffic Data and Acknowledgement/Retrans
mission Request Chunk
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On-Demand Traffic Data And Acknowledgement/Retrans
mission Request Chunk
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Cyclone Network Model
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Clock Synchronization

• Markers are sent to indicate the beginning and
  ending of a period
• A node obtains the clock information of upstream
  nodes
• A local clock rate is set to the average of
  incoming clock rates and its own rate
• A local clock phase is set considering clock
  phase information

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Connection Establishment/Termination
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Time Relationship Of Scheduling
t1
t2
Timeline of incoming link
d
t3
t4
Timeline of outgoing link (same speed)
t3
t4
Timeline of outgoing link (slower)
t3
t4
Timeline of outgoing link (faster)
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Single-Pass Scheduling Approach

• First available slot column assignment
• Assignment before reusing the buffer space

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Double-Pass Scheduling Approach
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Double-Pass Scheduling Approach
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Adaptation Layer

• Receive information from an application and
  provide the appropriate information to a temporal
  regulator in the form acceptable to a Cyclone
  network
• Specify temporal profile for a scheduled traffic
• Provide scheduled data chunks according to the
  temporal profile specified
• Detect bit-errors
• Initiate appropriate recovery mechanisms
• Initiate command control chunks
• Detect data loss for on-demand traffic
• Supports existing applications and communications
  with non-Cyclone networks

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Fault Handling

• Backup link approach
• line condition monitor
• backup link pointer
• automatic switching to backup
• Application-dependent recovery mechanism
• primary and secondary connections
• altering partial or entirety of a path
• Reader-writer flag for handling timing variability

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Summary Of Scheduling Techniques
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Performance Studies

• Data transfer
• Connection admission
• long term connections
• single node and multiple nodes

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Type Of Traffic Studied

• Regularly spaced traffic
• Random pattern traffic

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Regularly Spaced Traffic (S5-S7)
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(S7) 98.1 Loading
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Random Pattern (S8)
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Random Pattern (S9)
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Random Pattern (S10)
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Random Pattern (S11)
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Multiple Nodes

• Multiplied probability
• End-to-end delay is added

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Summary Of Performance Issues

• A couple of millisecond per node connection
  establishment overhead
• Close to 100 loading for identical, regularly
  spaced traffic
• Above 90 loading for regularly spaced traffic
• Above 80 loading for arbitrary pattern traffic,
  requesting 10 of bandwidth
• More than 50 of acceptance when links are 80
  loaded, requesting 10 of bandwidth

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Summary

• Time-based resource management approach in
  networking
• All aspects of a computer network required to
  support time-based resource management
• both scheduled and on-demand traffic
• end-to-end resource usage scheduling in time
• calendar-based data movements
• existing applications and communications with
  non-Cyclone network
• fault condition handling
• The feasibility of Cyclone technology
• end-to-end delay
• connection establishment overhead
• the probability of connection acceptance

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Advantages

• Temporal determinacy
• Loss free and jitter free end-to-end data
  delivery with minimal latency, without sustaining
  significant delays in connection establishment
• Nearly all of the bandwidth available for the
  actual transmission of data
• High loading without having any adverse impact on
  performance
• Well-suited for hardware implementation
• Highly scalable

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Limitations

• Temporal determinacy
• temporal profile of a connection be known ahead
• not current practice in networking
• Handling applications with significant
  variability
• Synchronous system

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Open Issues

• Alternative designs and policies
• Optimization of many system parameters
• Design tradeoff and optimization for specific
  applications
• Dynamic monitoring of performance
• Support existing internetworking protocols other
  than TCP/IP
• Extensions to point-to-point links and
  point-to-point connections
• Hardware design

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Value Added

• Time-based resource management
• Alternate way of managing resources in networking
• without requiring very accurate and highly
  synchronized clocks
• without consuming significant amount of bandwidth
  for handling timing variability
• Current applications with stringent timing
  requirement will perform better
• Lead to development of new classes of
  applications that are possible only when tight
  timing guarantee can be given

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Pathfinder
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4
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6
7
15
4
2
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15
6
4
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Connection Establishment/Termination