Monitoring and management of SDN is a challenging and active field of research. In this project, we have used Network Tomography techniques to enhance performance of SDN monitoring and management.
Modular Monolith - a Practical Alternative to Microservices @ Devoxx UK 2024
Network tomography to enhance the performance of software defined network monitoring and management
1. NETWORK TOMOGRAPHY TO ENHANCE THE
PERFORMANCE OF SOFTWARE DEFINED
NETWORK MONITORING AND MANAGEMENT
K M Sabidur Rahman
with Chaitrali Joshi and Tanjila Ahmed (ECS 273)
9/23/20161
3. 9/23/20163
Network Tomography
“It is the study of a network’s internal characteristics using information
derived from end point data.”
- Wikipedia
• Statistical theory and algorithms are used to estimate internal
characteristics of the network topology
• Flexibility of SDN can be used to make better results
4. 9/23/20164
Shortcomings of current measurement methods
• Impractical to measure packet delays at every router
• Proprietary routers are inflexible
• Geographic separation of routers
• Storing packet information at every node is expensive
• Memory constraints
• Causes congestion in communication
5. 3/14/165
Experimental Setup
• Topology setup using Mininet
• Single source multiple
receiver
• Controller for SDN
• Python based POX
remote controller
S2
H2 S1
S3
H3 H4
H1
6. 9/23/20166
EM Algorithm
•Iterative method for estimation of parameters in a statistical model
•It estimates the maximum likelihood of parameters
•Where the model depends on unobserved latent variable
•E step: Update the conditional expectation(log likelihood) of the parameter
by the given observation
•M step: Find the parameter that maximizes that quantity
7. 9/23/20167
EM Algorithm
y = observed end-to-end delay data
z = unobserved link delay(latent variable)
p=probability of delays on link i
Complete data likelihood can be factorized as :
where we have to estimate and z from end-to-end delay y
8. 9/23/20168
EM Algorithm
Complete data likelihood is dependent on likelihood of z as conditional pmf of y given z does
not have p parameter.
Where ,number of packets that faces delay j on link i
13. 9/23/201613
Future
•Use more data 100,1000,2000
•Use more complex topology
•Use SDN control mechanism to find the minimum measurement needed for
a network
•Explore temporal effects on delays