10.4 Software Defined Networking (SDN) Introduction

Software Defined Networking Overview

• Directly programmable: Network control is directly programmable because it is decoupled from forwarding functions.

• Agile: Abstracting control from forwarding lets administrators dynamically adjust network-wide traffic flow to meet changing needs.

• Centrally managed: Network intelligence is (logically) centralized in software-based SDN controllers that maintain a global view of the network, which appears to applications and policy engines as a single, logical switch.

• Programmatically configured: SDN lets network managers configure, manage, secure, and optimize network resources very quickly via dynamic, automated SDN programs, which they can write themselves because the programs do not depend on proprietary software.

• Open standards-based and vendor-neutral: When implemented through open standards, SDN simplifies network design and operation because instructions are provided by SDN controllers instead of multiple, vendor-specific devices and protocols.

The key advantages of Software-defined networking are

• Centralized control: The software-defined approach provides a single point of control for the entire SAN infrastructure that may span across data centers. The centralized control plane provides that programming logic for transferring the SAN traffic, which can be uniformly and quickly applied across the SAN infrastructure. The programming logic can be upgraded centrally to add new features and based on application requirements.

• Policy-based automation: With software-defined approach, many hardware-based SAN management operations such as zoning can be automated. Management operations may be programmed in the network controller based on business policies and best practices. This reduces the need for manual operations that are repetitive, error-prone, and time-consuming. Policy-based automation also helps to standardize the management operations.

• Simplified, agile management: The network controller usually provides a management interface that includes a limited and standardized set of management functions. With policy-based automation in place, these management functions are available in simplified form, abstracting the underlying operational complexity. This makes it easy to configure a SAN infrastructure. This also helps promptly modifying the SAN configuration to respond to the changing application requirements.