multi-layer network automation

Copyright © 2009 Ciena

Multi-Layer Network Automation

Loudon Blair

Symposium: Dynamic Multi-Layer Mesh Network ... Why, How, and When?

ECOC 2009, Vienna, Austria, 23rd September 2009

[email protected]

Copyright © 2009 Ciena 2

Multi-Layer NetworkService or Infrastructure | Client or Server

Multi-serviceMulti-pointOversubscription

Private, Secure BandwidthLow LatencyManaged Transparency

High Capacity Bandwidth Protocol TransparencyWholesale

Circuits

Service Applications

Packet

Lightpaths

Optical Network


Optical Network Evolution

ControlPlane

OpticalTransparency

ProtocolTransparency

Traditional SDH/SONET

Rings

Intelligent SDH/SONET

Mesh+ + -

Mesh

OTN

FCAPS

OAM

Protection

CoS

AutoProvisioning

SDH/SONETFraming

ConstraintsRestoration

OTN will replace SONET/SDH as foundation for optical services


Optical Transport Network (OTN) Definition

Client

ClientOH

Optical channel Payload UnitOH

Optical channel Data UnitOH FEC

Optical Multiplex Section

Optical Transmission Section

Optical Channel

Optical channel Transport Unit

OPU

ODU

OTU

OCH

OMS

OTS

Optical(Analog)Domain

Electrical(Digital)Domain

SONET/SDH, Ethernet, IP/MPLS

Overheadfor

OA&M

Traffic Payload ForwardError

Correction

ODU

FAS OTU OPU

Client Payload FEC

1234

1 7 8 14 15 16 17 3824 3825 4080

1234

1 7 8 14 15 16 17 3824 3825 4080

OTS OTS OTS

OMS

OCH

fiber

WDMMux/DemuxOTN standards defined by ITU-T G.872 and G.709


OTN Behaviors

OTU

ODU

OPUElectrical(Digital)Domain

Client TransparencySub-Wavelength ODU SwitchingHigh Efficiency GroomingPre-established Physical Links

OTS

OMS

OCh Client TransparencyFull-Wavelength OCh SwitchingWavelength Selective Bypass Unverified Physical Links

Optical(Analog)Domain


Three Architecture Options for OTN

CA B

SwitchedG.709

(Digital OTN)

SwitchedG.709

(Digital OTN)

DynamicWDM

(Analog OTN)

Framed G.709(Digital OTN)

FlexibleWDM

(Analog OTN)Static WDM (Analog OTN)

G.709 provides all dynamic capabilitiesWDM for capacity only

G.709 provides dynamic switchingWDM with reconfigurable connections

G.709 provides framing onlyWDM for all dynamic capabilities


OTN Economics & Power

Network Traffic (bits/second)

Cost or Powerper Bit

Electrical Sub-WaveSwitching Only

A

Hybrid CombinationWave + Sub-wave

Switching

B

10GOptical WaveSwitching Only

C40/100G

Important Conclusion: Stay on the Green Line


Control Plane Applications

OSSInitiated

1. Automated Self-Inventory 2. Automated Connection Management

MigratedTraffic

PlannedMaintenance Works

NetworkFailure

OSSInitiated

Auto-RestoredTraffic

3. Efficient Operations 4. Self-Healing Network


1. Automated Self-Inventory

New Switch Added Here

Automatic Topology Update

Network is Database of Record• Discover network element capabilities

and availability • Discover neighbor connections• Identify peer level port associations and

network layer client-server relationships• Distribute data to NEs and NMS

• Communicate network state updates • Create accurate & timely topological and

resource maps• Client inherits common server

characteristics• Define service-to-connection

associations• Customer service and SLA tracking


2. Automated Connection Management

Connection Confirmed

Click Source Click Destination

Point & Click Connections• Automate turn-up and tear-down of

connections• Signaled or Soft-permanent• Fast service activation

• Coordinate services across Packet, Circuit and Wavelength layers

• Heterogeneous infrastructure • Lowest cost routing• QoS awareness

• Multi-layer complicates path computation• Digital connection routing• Analog connection routing• Wavelength assignment• Optical impairment verification


3. Efficient Operations

Traffic Redirected for Maintenance

Planned Traffic Migration • Close cooperation between network

planning & field operations• Design tool planning• Control plane execution

• Planned Line Maintenance• Temporary re-route of traffic around

maintenance event• Temporarily disable links/nodes from use

• Network Defragmentation• Multi-layer traffic optimization• Periodically re-groom traffic on to cost-efficient

connections as demands change• Increases resource utilization & minimizes cost

per bit (Remember: Stay on Green Line)Switch off Node for Maintenance


4. Self-Healing Network

Double Network Failure

Connection Restored (Again)

Disaster Recovery• Mesh restoration across single- and

multiple- administrative domains• Sequence of multi-layer survivability

• Optical layer first, packet layer second• Packet layer first, optical layer second

• Re-establishment of protection path• Improve connection availability by restoring

BACKUP path of failed 1+1• Multi-layer control communication

• Layer decision: Hold off timers• Service priority: Contention control• Real-time alerts: AIS, Pre-FEC BER• Routing impact: Latency, SRLG


Summary

New Breed of Network Elements that participate in Multiple Network LayersIncludes Packet, Circuit and Lightpath

Multi-Layer Switching Improves Cost & Power per BitHybrid Combination of Electrical and Analog OTN Networking

Four Applications for Control Plane AutomationAutomated Self-Inventory

Automated Connection Management

Efficient operations

Self-Healing Network

multi-layer network automation

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