Transcript On the Management Issues over Lambda Networks

2005 / 08 / 23
On the Management Issues
over Lambda Networks
Te-Lung Liu
Associate Researcher
NCHC, Taiwan
1
Overview
 Introduction
 Functions of Optical Management Plane
 Implementation
 Applications
 Conclusions
2
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.
3
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

4
Optical
Transport
Network
Data Plane
(forwarding only)
Q
Y
X
virtual topology
B
P
A
C
D
E
Physical topology
Control plane
(routing + signaling)
5
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.
Management Plane
Control Plane
Data Plane
Optical Layer (SDH,DWDM…)
Physical Layer
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Functions of Management Plane


Virtual topology visualization
Lightpath resources and bandwidth management


Alarm Notification and Error Indication


Trap analysis
Lightpath survivability


SDH channels and DWDM wavelengths
Protection and restoration
Performance measurement and monitoring

Re-route the LP if the performance falls below a certain
level
7
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 rerouting the failed lightpath dynamically is another way
to achieve survivability.
8
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
Pacific Wave
CANARIE
StarLight
NTU
NCU
CANARIE
Sinica
Taipei
NCTU
NTHU
Hsinchu
NTU
1.25G
NCHU
Taichung
NCNU
MAN LAN
Tainan
CCU
NCKU
NSYSU
Pacific Wave
South
10
Distribution of TW-US Lightpaths
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
TW-US lightpaths Layout
11
Tainan to NYC: under normal operation
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
Initial LP provisioning from TN to NY
12
Event 1: LANYC fails
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
A failure occurs on the unprotected LA-NY link
13
Event 2: re-route kicks off
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
The affected TN-NY LP is dynamically re-routed
14
Inter-Domain Operation (1)
A
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
A LP is provisioned from TN to an interdomain site A
15
Inter-Domain Operation (2)
A
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
Node NY-15454 failed
16
Inter-Domain Operation (3)
A
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
TN-NY LP is re-routed as TN-STARLIGHT
17
Inter-Domain Operation (4)
A
SEATTLE
STARLIGHT
TP-15600
Taipei
NY
SFC
Chicago
TN-15600
TN-15454
LA
The peer domain re-routes their LP to STARLIGHT
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Implementation
update
Control Plane
Visulization
Bandwidth Management
Optical Equip.
query
trap
Performance Monitoring
Reroute request
trigger
Alarms and Error Indication
Restoration
activate
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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
20
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.
21
Thank you !
Comments and Suggestions?
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