1. Distributed Control Plane
Differentiated Reliability in Distributed Survivable Optical Mesh Networks
Dhruvish Shah, Dr. Marco Tacca and Dr. Andrea Fumagalli
Optical Networks Advanced Research (OpNeAR) Lab
Node Architecture
Network Architecture
Distributed Control Plane 4 1 3 2 5
Free Queue
Busy Queue
Request Dropped
Advantages:
No Central Controller
Less signaling compared to centralized counterpart
Less set-up delay
Limitations:
More connection blocking
Complex Node Architecture
Distributed Control Plane
IP Over WDM Mesh Network with Distributed Control Plane
Multiple wavelengths and fibers per link
Per source node queue for fairness in blocking
On-Line Optimized Routing and Wavelength Assignment (RWA) based on Differentiated Reliability (DiR) and Shared Path Protection (SPP)
Simulation Scenario
Network Protocols
Network Protocols (Contd.)
Berkeley Network Simulator (NS2)
19 Node European Topology with 39 bidirectional
links
Poisson arrivals, uniformly distributed among nodes,
exponential demand lifetime
One fiber in each direction of propagation
Maximum Conditional Failure Probability (MCFP)
of 0.03 assuming single link failure scenario allowing
single unprotected link on working lightpath
RWA:
Source computes lightpath resources
Optimize network resources with Simulated Annealing
Linear (LB) and Matrix DPM approach
CRANKBACK:
Contentions cause lightpath set-up failure
Reattempt to set-up lightpath until successful
Avoid using the resource which was contended
for successive RWA computations
Aggressive reattempts
Ensures fairness for longer lightpaths
RSVP and Modified OSPF:
Destination initiated reservation
Event driven node based OSPF for data synchronization
Summary
Comparison of DSPP-DiR with DSPP
Distributed and Centralized Control Planes
Probability Distribution
With only one unprotected link the
DSPP-DIR scheme reduces blocking
dramatically
As traffic becomes faster, due to lack of
faster synch blocking increases
The Distributed Control Plane performs
almost same as its Centralized counterpart
at light load, blocking increases more
rapidly at higher load
Single buffer queue at each source node
and CRANKBACK ensure fairness among
nodes