The main scope of up-gradation to the advanced computer networks is to make the technical advancement in the network management and so managing the traffic control (that is the control plane and data or forwarding plane) while abridging it in the Multi-Controller Domain. SDN refers to the isolation of the network control plane from the forwarding plane, with a control plane overseeing many networking systems. This paper investigates how new improvements in SDN and the programmability of networks can be helpful to abridge tasks, improve dexterity, and encounter new task necessities within the U.S. Department of Defense (DoD) and open networks. These improvised network services across the digital network entail a multi-controller domain. This paper represents the research in SDN and multi-controller domain, aiming at OpenFlow Protocol and its upcoming challenging tasks.

1. Presentation
on
SDN : Multi-Controller
Domain
By
Sandeep Maurya (GE-
20161983)
Computer Science Dept. ( M-tech
1st Yr )

2. Table of Content
• Introduction
• Background
• Data Plane
• Control Plane
• Mechanism
• Problems ………??
• Management plane
• Motivation
• Organization
• OpenFlow
• SDN Controllers
• Working with “MININET”
• Load Balancer Strategies
• Applications
• Conclusions and Future Scope
• SDN Research areas

3. Introduction
“SDN is the substantial separation of the network control plane
from the data plane, and where a control plane panels several
networking devices”
Software-Defined Networking (SDN) is the evolving
networking paradigm that greatly shortens network
management jobs.

6. Background
Data plane: processing and delivery of packets with local forwarding state
 Forwarding state + packet header  forwarding decision

7. Control plane: compute the state in routers (forwarding state)
 Each router determines how and where packets is to be forwarded.
 Routing, traffic engineering, firewall state.
 Implemented with distributed protocols, manual configuration

8. Control Plane Mechanisms
Variety of goals:
Routing: distributed routing algorithms.
Isolation: ACLs, VLANs, Firewalls.
Traffic engineering: adjusting weights, MPLS.
No modularity, limited functionality
Control Plane: mechanism without abstraction
Too many mechanisms, not enough functionality.

9. SDN: Two Control Plane
Abstractions
 Abstraction: global network view
 Provides information about current network
 Implementation: “Network Operating System”
 Runs on servers in network (replicated for reliability)
 Abstraction: forwarding model
 Provides standard way of defining forwarding state
 Use of OpenFlow: Specification of <match,action> flow entries

10. The Control Plane Problem
Control plane must compute forwarding state. To accomplish its
task, the control plane must:
Figure out what network looks like (topology)
Figure out how to accomplish goal on given topology
Tell the swtiches what to do (configure forwarding state)
What components do we want to reuse?
Determining the topology information
Configuring forwarding state on routers/switches

11. Management plane: performing the operation and maintenance of network.
 Logging to each and every router for configuration .
 To add a new route changes has to be made on every router.

12. Motivation
Networks are hard to manage
 Computation and storage have been virtualized
 Creating a more flexible and manageable infrastructure
 Networks are hard to evolve
 Ongoing innovation in systems software
 New languages, operating systems, etc.
 Routing algorithms change very slowly
 Networks design not based on formal principles
 OS courses teach fundamental principles
 Mutual exclusion and other synchronization primitives
 Files, file systems, threads, and other building blocks
 Networking courses teach a big bag of protocols
 No formal principles, just general design guidelines

13. Organization
 The Open Network Foundation (ONF) describes the SDN as a separation of the control plane and the
data plane.
 Conventional network devices have a unified control plane and data plane.
 In this typical SDN architecture, yet the network intelligence is logically consolidated into a controller,
and there is a physical parting between the control plane and the data plane.
 OpenFlow is the protocol that stipulates the connections between the control plane running in the
controller and the organization.

14. OpenFlow Basics

15. Working with “MININET”
What is MININET?
MININET offers a virtual simulation and development environment for SDN.
MININET executes real code comprising of standard Unix/Linux network applications
as well as the real Linux kernel.

16. SDN Controllers
 Controllers are the fundamental module of an SDN.
 They supervise the performance of the entire network and implement the
decisions to achieve the desired state for the network.
 They are a logically centralized program that provides services and applications
for controlling the network.
 It is crucial to highlight that a logically centralized program does not mean that we
have a centralized system.
 The controller can be dispersed and simulated for fault tolerance and/or better
functioning.
 In any case, applications are written as if the network view was collected on a
single machine.
Some different SDN Controllers are NOX, HyperFlow, ONIX.

17. SDN : Multi-Controller

18. Example: New Data Center
Cost
200,000 servers
Fanout of 20 10,000 switches
$5k vendor switch = $50M
$1k commodity switch = $10M
Savings in 10 data centers = $400M
Control
More flexible control
Tailor network for services
Quickly improve and innovate

19. Load Balancer Strategies
To efficiently schedule the request of routing from a client to the particular servers in
an enhanced way, several load balancing approaches are used that is as follows:
RANDOM STRATEGY: From a list of available servers, the Load Balancer will randomly
choose a particular server for sending requests. This policy has large overheads.
ROUND-ROBIN: In this, each server receives the request from clients in a circular mode.
The requests are allocated to various available servers on a round-robin base.
WEIGHTED ROUND-ROBIN: In this, each server receives the request from the client
based on criteria that are fixed by the site administrator. In another word, A Static weight
is assigned to each server in Weighted Round Robin (WRR) policy

20. Conclusion and Future
Scope
 SDN load balancer resolves many difficulties of traditional load balancers since traditional load
balancers use dedicated hardware.
 As are many cases with the help of most commercial load balancers, the load balancer can also be
a single point of failure.
 To eliminate this problem in the future one can use multiple controllers instead of a single
controller.
 In case of one controller failing, an alternative machine will take over the functioning of the
controller and continue routing traffic.
 Software-defined networking is based on the notion of decoupling the control plane and the data
plane and, following that, centralizing the whole control plane in one single controller that
operates the entire network.
 Network researchers and designers will have to deal with many difficulties that distributed
architectures face in improving a multi-controller network.

21. SDN Research areas
Controller scalability
 reduce messages sent to
controller
 switch/CPU design approaches
Network Updates
Programming
Testing/Debugging
Traffic Management/QoS
 Flow Scheduling
 Load Balancing
 Transport Protocol
Monitoring
Security
SDN
architecture
SDN
applications

22. THANK YOU