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Traditional vs. Software Defined Networking (SDN)

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This article compares traditional networking with software-defined networking (SDN), highlighting the key differences between the two approaches.

traditional networking

Figure 1 illustrates the layers within a traditional networking device. These networks are typically static and include three distinct planes:

  • Control Plane: Responsible for routing decisions and network intelligence.
  • Management Plane: Handles device configuration, monitoring, and management tasks.
  • Data Plane: Forwarding the actual data packets based on the decisions made by the control plane.

Software Defined Networking

Figure 2 depicts the architecture of Software Defined Networking (SDN). In contrast to traditional networking, SDN features a decoupled architecture with:

  • Data Plane: A simplified layer responsible solely for forwarding data.
  • OpenFlow API: A standardized interface allowing communication between the data plane and the controller.
  • Controller: A centralized component housing both the control and management planes.
  • Application Layer: Applications that leverage the SDN infrastructure.

The following table summarizes the core differences between traditional networking and software-defined networking.

Traditional NetworkingSoftware Defined Networking
Static and inflexible networks.Programmable networks during deployment and runtime.
Not ideal for new business ventures.Supports new business ventures through flexibility.
Limited agility and flexibility.High agility, flexibility, and virtualization.
Hardware appliances.Configured using open software.
Distributed control plane.Logically centralized control plane.
Uses custom ASICs and FPGAs.Uses merchant silicon.
Relies on protocols.Uses APIs for configuration.