11

On the Management Issues over Lambda Networks

2005 / 08 / 23

Te-Lung LiuAssociate Researcher

NCHC, Taiwan

22

Overview Introduction Functions of Optical Management Plane Implementation Applications Conclusions

33

Introduction Lambda networking enables e-Science

applications that require huge data transfer with QoS guarantee.

Dedicated network channels called lambdas or lightpaths are created as a dedicated leased line without jitter and congestion.

Lightpaths are provisioned by control plane while traffics travel through data plane.

44

Control Plane and Data Plane Control plane chooses and reserves a

deterministic, bandwidth-guaranteed path for a given connection request. routing + signaling messages are passed through "control channel"

over physical topology Data plane is separated from control plane in order

to speed up forwarding. network is now viewed as a collection of "lightpaths" Virtual topology is depicted by connecting lightpaths

and routers in between

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AB

CD

E

Control plane(routing + signaling)

OpticalTransportNetwork

Physical topology

Data Plane(forwarding only)

virtual topology

P

Q

X Y

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Management Plane

The Emergence of Management Plane

Although functions of routing, signaling and forwarding are fulfilled by control plane and data plane, we still need some management functions such as resource/bandwidth maintenance, failure notification and lightpath survivability… etc.

Physical Layer

Optical Layer (SDH,DWDM…)

Control Plane Data Plane

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Functions of Management Plane

Virtual topology visualization Lightpath resources and bandwidth management

SDH channels and DWDM wavelengths Alarm Notification and Error Indication

Trap analysis Lightpath survivability

Protection and restoration Performance measurement and monitoring

Re-route the LP if the performance falls below a certain level

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Lightpath Survivability In general, lightpath survivability is achieved by

protection. fast switching time (<50ms) Protection by carrier

• extra cost Protection by SONET/SDH

• In the absence of failure, the protected bandwidths are wasted

To improve bandwidth utilization, restoration by re-routing the failed lightpath dynamically is another way to achieve survivability.

99

Lightpath Restoration Not every lightpath is eligible for restoration.

A rational business model: only those requiring QoS guarantee are candidates for restoration

Exact location of error is determined through root-cause analysis of traps in order to choose the candidate LPs for restoration.

For each restorable LP, the re-route path can be either statically stored in a given table or dynamically calculated.

Intra-domain restoration vs. inter-domain restoration

1010

TWAREN / TAIWANLight Lambda Testbed

Taipei

Hsinchu

Taichung

Tainan

NTU

NSYSUNCKU

CCU

NCNU

NCHU

NTHU

NCTUNCU

SinicaNTU

StarLightStarLight CANARIECANARIE

CANARIECANARIEPacific WavePacific Wave

MAN LANMAN LAN

3*STM-4+2*STM-1

3*STM-4+3*STM-1 2.5G

2G

1.25G

1.25G1.25G

1.8G

2.5G

Pacific Wave Pacific Wave SouthSouth

1111

Distribution of TW-US Lightpaths

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

TW-US lightpaths Layout

1212

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

Initial LP provisioning from TN to NY

Tainan to NYC: under normal operation

1313

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

A failure occurs on the unprotected LA-NY link

Event 1: LANYC fails

1414

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

The affected TN-NY LP is dynamically re-routed

Event 2: re-route kicks off

1515

Inter-Domain Operation (1)

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

A LP is provisioned from TN to an interdomain site A

A

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Inter-Domain Operation (2)

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

A

Node NY-15454 failed

1717

Inter-Domain Operation (3)

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

A

TN-NY LP is re-routed as TN-STARLIGHT

1818

Inter-Domain Operation (4)

TN-15454

TN-15600

TP-15600 SFC

SEATTLE

LA

STARLIGHT

NY

Chicago

Taipei

A

The peer domain re-routes their LP to STARLIGHT

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Implementation

Visulization

Alarms and Error Indication

Bandwidth Management

Performance Monitoring

Restoration

Control Plane

update

trigger

activate

Reroute request

Optical Equip.

trapquery

2020

Applications Lambda Testbeds

Network automation can be achieved with management plane.

Optical Exchanges The optical exchange administrators have to

monitor the connectivity and the exchange sites may have to participate in inter-domain operations if the clients are connected without O/E/O conversion.

Global Collaborations

2121

Conclusions Lambda networks connect e-Science

applications across different continents with service level guarantee. We need a way to monitor the status of the

virtual topology provisioned over lambda networks.

In this paper, elements of optical management plane are discussed.

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Thank you !

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