Introducing OpenShift Software-Defined Networking

Software-defined networking (SDN) is a dynamic, manageable, cost-effective, and adaptable networking technology suitable for the high-bandwidth, dynamic nature of today’s applications. By using an SDN architecture, an IT operations team can control network traffic in complex networking topologies through a centralized panel, rather than handling each network device, such as routers and switches, manually.

Rapidly growing mobile content, server virtualization, and hybrid cloud services are some of the trends leading the networking industry to reconsider network architectures. The traditional networking architecture is built mainly on multiple layers of network switches in a hierarchical topology. But it’s harder to address rapidly increasing application workloads from multiple and hybrid infrastructures (like the cloud) in a hierarchical architecture.

OpenShift implements a software-defined network (SDN) to manage the network infrastructure of the cluster and user applications. Software-defined networking is a networking model that allows you to manage network services through the abstraction of several networking layers.

It decouples the software that handles the traffic, called the control plane, and the underlying mechanisms that route the traffic, called the data plane. Among the many features of SDN, open standards enable vendors to propose their solutions, centralized management, dynamic routing, and tenant isolation.

In OKD, the SDN solves the following five requirements:

  • Managing the network traffic and network resources programmatically, so that the organization teams can decide how to expose their applications.
  • Managing communication between containers that run in the same project.
  • Managing communication between pods, whether they belong to a same project or run inseparate projects.
  • Managing network communication from a pod to a service.
  • Managing network communication from an external network to a service, or from containers to external networks.

The SDN implementation creates a backwards-compatible model, in which pods are akin to virtual machines in terms of port allocation, IP address leasing, and reservation