Over the last decade, there has been a need for a network operating system that supports operational agility and efficiency through seamless integration with existing tool chains. Service providers have been looking for shorter product cycles, agile workflows, and modular software delivery; all of these can be automated efficiently. The 64-bit Cisco IOS XR that replaces the older 32-bit QNX version meets these requirements. It does that by providing an environment that simplifies the integration of applications, configuration management tools, and industry-standard zero touch provisioning mechanisms. The 64-bit IOS XR matches the DevOps style workflows for service providers, and it has an open internal data storage system that can be used to automate the configuration and operation of the device hosting an application.

While we are rapidly moving to virtual environments, there is an increasing need to build applications that are reusable, portable, and scalable. Application hosting gives administrators a platform for leveraging their own tools and utilities. Cisco NCS 540 routers support third-party off-the-shelf applications Application hosting is offered in two variants: Native and Container. An application hosted on a network device can serve a variety of purposes. This ranges from automation, configuration management monitoring, and integration with existing tool chains.

Before an application can be hosted on a device, the following requirements must be met:

• Suitable build environment to build your application

• A mechanism to interact with the device and the network outside the device

When network devices are managed by configuration management applications, such as Chef and Puppet, network administrators are freed of the task of focusing only on the CLI. Because of the abstraction provided by the application, while the application does its job, administrators can now focus on the design, and other higher level tasks.

This section describes the architecture of the 64-bit IOS XR and the architecture used for application hosting.

64-bit IOS XR Architecture

IOS XR provides Linux containers for application hosting through a hypervisor. Each container provides a unique functionality. The 64-bit host Linux (hypervisor) is based on the Wind River Yocto distribution, and works well with embedded systems. The various containers that are offered on the host Linux, are explained in this section.

The following figure illustrates the 64-bit IOS XR architecture.

• Admin Plane: The admin plane is the first Linux container to be launched on booting IOS XR. The admin plane is responsible for managing the life cycle of the IOS XR control plane container.

• XR Control Plane: XR control plane is a contaitner that consists of routing information.

• Data Plane: The data plane substitutes and provides all the features of a line card in a modular router chassis.

• Third-Party Container: You can create your own Linux container (LXC) for hosting third-party applications and use the LC interfaces that are provided.

Apart from the Linux containers, several interfaces are offered on the host Linux.

Application Hosting Architecture

The 64-bit IOS XR introduces the concept of using containers on the 64-bit host Linux (hypervisor) for hosting applications in the XR control plane and in the third-party.

The Third-Party Application (TPA) IP is configured so that applications can communicate outside XR through the fwdintf interface, which is bound to the Loopback0 interface of XR. All applications communicate with XR through the fwd_ew interface, which is bound to the Loopback1 interface of XR.