On the Management Issues over Lambda Networks
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Transcript of On the Management Issues over Lambda Networks
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On the Management Issues over Lambda Networks
2005 / 08 / 23
Te-Lung LiuAssociate Researcher
NCHC, Taiwan
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Overview Introduction Functions of Optical Management Plane Implementation Applications Conclusions
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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.
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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.
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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
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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
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Distribution of TW-US Lightpaths
TN-15454
TN-15600
TP-15600 SFC
SEATTLE
LA
STARLIGHT
NY
Chicago
Taipei
TW-US lightpaths Layout
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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
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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
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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
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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
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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
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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
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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
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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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