A Practical Design and Implementation Approach

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A Practical Design and Implementation
Approach Marc Teichtahl marc.teichtahl_at_versatel.n
l marct_at_layerthree.com
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Presentation overview

• Design overview
• Why packet rings ?
• Current designs
• Removing the transport layer
• DTP basics
• Robustness and resilience
• Aplanned case study

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Design Overview
Design Brief
effect the migration from traditional
transmission technologies to a next generation
platform optimized for the transmission of purely
packetized data
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Why packet rings ?

• Reduction in capital expenditure
• No more SDH/SONET ADMs
• More efficient use of bandwidth
• statistical multiplexing and spatial resuse
• Single management infrastructure

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Current Design
SDH Tributaries
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Whilst robust, this design tends to be
inefficient when dealing with purely packetized
data

• Dedicated protection time slots reserve half the
  ring at all times.
• Fixed size Point to Point circuits provisioned
  regardless of actual bandwidth use.
• Cost and complexity reduced as we remove
  transport layers from the network.

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Working
Provisioned Circuit
ADM
ADM
Protection
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Removing the transport layers
Today
Traditional
Tomorrow
IP
IP Over ATM
POS
IP
ATM
IP
IP-OG
IP
SONET
ATM
SONET
Optical
Optical
Optical
Optical
Lower Cost, Complexity, Overhead
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DPT Basics
Inner Ring Control
Outer ring data
Outer ring control
Inner ring data
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2 Rings - Inner and Outer

• Data and control in opposite directions
• Both fibers used concurrently
• Accelerated control propagation for adaptive
  bandwidth utilization and self-healing.

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Framing

• Utilizes SONET/SDH framing
• Runs over all key fiber transport technologies
• Dark Fiber
• WDM
• SONET/SDH point to point and ring

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Bandwidth Multiplication

• Spatial re-use - SRP Traditional ring
  technologies use source stripping. This is in
  efficient, SRP uses destination stripping.
  Destination stripping allows the destination
  node to remove the packet from the ring freeing
  up bandwidth on other non-related paths.

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Bandwidth Multiplication

• Dual Fiber Both fibers carry working traffic.
  This is unlike SONET which uses dedicated
  protection bandwidth. Implemented in an
  existing network DTP can yield 12 (x2)
  bandwidth multiplier.

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Bandwidth Multiplication

• Statistical Multiplexing No TDM and no
  provisioned circuitsProvides for statistical
  over subscriptionCan handle elastic burst
  requirements

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Robustness and Resilience

• Intelligent Protection Switching (IPS)Proactive
  monitoring and and self-healing throughstandard
  SONET/SDH overhead bytes.50ms self-healing
  layer 1 wrappingProtection switching hierarchy
  for multiple concurrent failures

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Robustness and Resilience

• Intelligent Protection Switching (IPS)Doesnt
  rely on SONET overhead bytes allowing foruse
  non-SONET infrastructure such as WDM50ms IP
  restorationMulti-layer aware, the router can
  now see all 3 layers

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A planned case study
4 Phase implementation plan

• Single node SDH tributary
• Semi-Hybrid transport network
• Hybrid network
• Full DPT network

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Single node SDH tributary
SDH
DPT
IP
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Semi-Hybrid transport network
SDH
DPT
DPT
IP END TO END
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Hybrid network
IP only
IP only
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Full DPT network
OC-12
OC-12
OC-12
OC-12
IP ONLY END TO END TRANSPORT LAYER IS COMPLETELY
TRANSPARENT
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Amsterdam

• 3 phase implementation
• Semi-hybrid trial Amsterdam -gt Brussels
  Point to point
• Hybrid trial Amsterdam -gt Brussels Loop
• Full DTP Full DTP loop

Den Haag
OC-12
Rotterdam
OC-12
OC-12
Antwerp
OC-12
Brussels
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Presentation available at ftp//ftp.layerthree.co
m/pub/nanog16.ppt email me marct_at_layerthree.com