Cisco introduced a new open standards-based protocol for Application Centric Infrastructure (ACI) called OpFlex, which the company submitted to the Internet Engineering Task Force (IETF) for consideration last week.
Cisco has a stake in the future of software defined networks (SDN), so it is not surprising the company is taking a lead in helping to create protocols and standards that work within SDN. However, OpFlex is not just a Cisco initiative. It has a few well-known backers such as Microsoft, IBM, and SunGard who are, according to Cisco, actively involved in the standardization process.
[Read: Software Defined Networking: Introduction to OpenFlow]
The OpFlex standards are to help fill a gap in the current SDN model, which Cisco describes as "an imperative control model with a centralized controller and distributed network entities that support the lowest common denominator feature set across vendors such as bridges, ports and tunnels."
The issue Cisco sees with the existing imperative control model is when a network grows (scales) the controller becomes a bottleneck due to the need to handle more processes. The larger the network grows, the bigger the impact on the controller's performance, which then negatively affects the network.
Additionally, the current SDN model requires application developers to write code to describe application, operation, and infrastructure requirements in low-level constructs the controller will understand. This introduces added manual steps and learning processes that can have a negative impact on an organization's ability to make quick changes to infrastructure or to manage growth within the data center.
The ACI model abstracts applications, operations, and infrastructure, which is another way of saying, to keep things simple the model only wants minimum essential information about each item it interacts with in order to interact with it. With the OpFlex standard, the complexity remains with the distributed edge devices and allows for additional network resiliency by avoiding single points of failure or as Cisco puts it, "the data forwarding can still continue to happen even if there is no controller." Additionally, the ACI model would automatically deliver self-documenting policies that are deployed or cleaned up from devices as needed.
Finally, Cisco also announced that the following products will support the new protocol:
Cisco Application Centric Infrastructure, Nexus 9000 Series;
Cisco Nexus 1000V;
Cisco ASR 9000 Series;
Cisco Nexus 7000 Series;
For more information on OpFlex, check out this whitepaper from Cisco and this blog post from Shashi Kiran.