Networks today must increasingly provide agility and flexibility without compromising performance, security, scalability, or stability. While most software-defined networking (SDN) solutions tackle this problem by creating software overlay solutions, Cisco believes it has missed an opportunity to simplify the way networking connectively is defined and created Cisco OpFlex.
In its white paper, “Cisco OpFlex: An Open Policy Protocol,” the company outlines the fundamentally different SDN approach it uses in its Application Centric Infrastructure (ACI). Employing a model based on declarative control, ACI asks each object to achieve a desired state and make a promise to reach the state, without precisely telling the object how to do so.
The white paper likens declarative control to an airport control tower: Air traffic controllers in the tower will tell pilots to take off or land in particular places, but the actual job of flying and landing the planes belongs to the independent pilots.
Likewise, a system managed through declarative control asks underlying objects to handle their own configuration state changes rather than centralizing all the network control functions on the controller. To implement declarative control, Cisco created OpFlex as a mechanism to transfer abstract policy from a network policy controller to a set of smart devices.
OpFlex:Open Policy Protocol
- Explains it’s logical model
- Summarizes it’s RPC messages
- Describes a sample virtual leaf architecture for ACI
- Highlights a sample data center interconnect setup with ACI
Whereas software overlays mimic the same Layer 2 and 3 constructs used in networking today, Cisco believes declarative control through OpFlex offers a more effective way for managing complex infrastructure and is supported by partners including Microsoft, Red Hat, Citrix, and F5.