Software Defined Networks

Dr. Uttam Ghosh, CDAC, Bangalore uttamg@cdac.in

Outline

Networking Planes

OpenFlow

Software Defined Network (SDN)

SDN Origin

What is SDN?

SDN Architecture

SDN Operation

Why We Need SDN?

SDN Integration

Conclusion

Planes of Networking

• Data Plane:

Responsible for forwarding

and processing data.

Runs at line rate (Fast Path).

Implemented using special

hardware TCAMs.

• Control Plane:

Responsible for making forwarding decisions (routing table) and

programming (packet handling policies) data plane

Handled by CPU

• Management Plane:

Responsible for provisioning and monitoring of networks

Fault, Configuration, Accounting, Performance and Security(FCAPS).

Instantiate new devices and protocols (turn devices on/off)

Problem of Legacy Network Devices

Too complicated

Control plane is implemented with complicated S/W and ASIC

Closed platform

Vendor Specific

Hard to modify (nearly impossible)

Hard to add new functionalities

New proposal: OpenFlow/Software Defined Networking

Legacy Network and SDN

OpenFlow: Key Ideas

Separation of control and data planes

Centralization of control

Flow based control

OpenFlow: Separation of Control and Data Planes

Components: Controller, OpenFlow switch and secure channels.

Control logic is moved to a controller.

Switches only have forwarding elements.

One expensive controller with a lot of cheap switches.

OpenFlow is the protocol to send/receive forwarding rules from

controller to switches.

OpenFlow: Bootstrapping

Switches require initial configuration: Switch IP address, controller IP

address and default gateway

Switches connect to the controller

Switch provides configuration information about ports

Controller sends a LLDP request to all neighbors (switches)

Controller determines the topology from LLDP responses

Origins of SDN

SDN originated from OpenFlow

Centralized Controller

Easy to program

Change routing policies on the fly

Software Defined Network (SDN)

Initially, SDN=

Separation of Control and Data Plane

Centralization of Control

OpenFlow to talk to the data plane

Now the definition has changed significantly.

What is SDN?

The physical separation of the network control plane from the

forwarding plane, and where a control plane controls

several devices.

1. Directly programmable

2. Agile: Abstracting control from forwarding

3. Centrally managed

4. Programmatically configured

5. Open standards-based vendor neutral

SDN Architecture

SDN Architecture (Contd..)

SDN Operation

Why We Need SDN?

1. Virtualization: Use network resource without worrying about

where it is physically located, how much it is, how it is

organized, etc.

2. Orchestration: Should be able to control and manage

thousands of devices with one command.

3. Programmable: Should be able to change behavior on fly.

4. Dynamic Scaling: Should be able to change size, quantity

5. Automation: To lower OpEx minimize manual involvement

Troubleshooting

Reduce downtime

Policy enforcement

Provision / Re-provision /Segmentation of resources

Add new workloads, sites, devices, and resources

Why We Need SDN? (Contd..)

6. Visibility: Monitor resources, connectivity

7. Performance: Optimize network device utilization Traffic engineering/Bandwidth management

Capacity optimization

Load balancing

High utilization

Fast failure handling

8. Multi-tenancy: Tenants need complete control over their addresses, topology, and routing, security

9. Service Integration: Load balancers, firewalls, Intrusion Detection Systems (IDS), provisioned on demand and placed appropriately on the traffic path

Definition of SDN

SDN is a framework to allow network administrators to

automatically and dynamically manage and control a large

number of network devices, services, topology, traffic

paths, and packet handling (quality of service) policies

using high-level languages and APIs. Management

includes provisioning, operating, monitoring, optimizing,

and managing FCAPS (faults, configuration, accounting,

performance, and security) in a multi-tenant environment.

Dynamic and Quick

Integration of SDN

Cloud Computing

Internet of Things

Sensor Networks

Mobile Computing

Named Data Networking (NDN)/ Information Centric

Networking (ICN)

SDN in Wi-Fi

http://www.merunetworks.com/products/technology/sdn/

SDN in MANET/VANET

• Challenges: Unreliable: Controller-switch connection is wireless

Complex: Node mobility adds complexity

• Solution: Ian Ku, You Lu, and Mario Gerla. "Software-Defined Mobile Cloud: Architecture,

Services and Use Cases“, in IWCMC’14.

Two Interfaces: 1) LTE for Controller; 2) WiFi for Data Plane

Wireless node has an local optional SDN Controller.

Wireless Node

SDN in MANET/VANET

Conclusion

SDN?

New network architecture

Dynamic flow control, programmability, and more

Usually employ into a wired-network environment (Data

Center)

Many researchers try to move this idea into a wireless

network environment

SDN is the tool to develop new applications and solutions to

longstanding problems. In this respect, our work is just

beginning.

References

[1] Ian Ku, You Lu, and Mario Gerla. "Software-Defined

Mobile Cloud: Architecture, Services and Use Cases“, in

IWCMC’14.

[2] Prof. Raj Jain, “Introduction to Software Defined

Networking (SDN)”.

[3] Qin, Zhijing, et al. "A Software Defined Networking

Architecture for the Internet-of-Things."

Thank You