In Chapter 5, Getting Started with OpenDaylight, we showed how OpenDaylight (ODL) addresses the key needs for SDN by supporting network abstractions, rich APIs, and multi-vendor support. ODL acts as a controller for a distributed control plane, and also an on orchestrator for Virtual Network Functions (VNFs) and Service Function Chaining (SFC). Let us now focus our attention on a SDN platform called the Open Network Operating System (ONOS). While ODL primarily solves data center use cases, ONOS is architected for the carrier-grade networks requirements of performance, high availability, and scale, with well-defined abstractions.
In this chapter, we will start with an introduction to ONOS and its architecture, and we will then explore ONOS integration with Open vSwitch (OVS). We will conclude the chapter with a quick introduction to using ONOS in an OpenStack environment. We will cover the following topics in this chapter:
- Introduction to ONOS
- ONOS architecture
- Installing ONOS
- Using ONOS to manage Open vSwitch (OVS)
- ONOS and OpenStack
Service provider networks need agile network architectures designed to cater to exponentially-growing bandwidth demands driven by mobile devices and content distribution across the cloud. Moreover, the business imperative for creating new revenue streams offering innovative services economically requires that the network infrastructure be architected to cater to these wide-ranging requirements.
SDN provides a framework for catering to these requirements. ONOS is created with the intent of leveraging an SDN framework and enhancing it for carrier-grade service requirements providing programmable, efficient, and agile network services:
Figure 1: ONOS architecture overview
ONOS is an open source project under the Open Networking Lab (ON.Lab) to accelerate innovation in SDN with the objective of reducing the costs related to building and operating networks. It is developed by a partnership of service providers (AT&T, NTT Communications, Verizon), network vendors (Ciena, Cisco, Ericsson, Fujitsu, Huawei, Intel, NEC, Nokia), network operators (Internet2, CNIT, CREATE-NET), and collaborators. It is supported by the Open Networking Foundation (ONF). ONOS is modeled as a complete network operating system providing features beyond the SDN controller. ONOS is an SDN network operating system (OS) for carrier-grade and mission-critical networks.
The following diagram outlines the functional progression from the OpenFlow Controller, focusing on providing the OpenFlow control functionality to the SDN Controller supporting distributed network control and to the SDN Framework supporting extensibility and network abstraction, and finally, to the Network Operating System:
Figure 2: SDN Controller evolution
ONOS is architected to provide abstraction APIs for SDN application development, APIs to manage, monitor and program network devices. It provides virtualization, isolation, secure access, and abstraction, to networking resources managed by the network operating system. ONOS multiplexes hardware resources and software services among the SDN applications. It supports configuring network policies based on application intent and processing network events.
It is designed to operate with white box network devices to drive down the costs associated with proprietary solutions and achieve cloud-style economies of scale. ONOS has a flexible architecture that allows new networking hardware to be easily integrated into the SDN framework. Software-based orchestration reduces the OPEX costs. ONOS is implemented in Java and licensed under Apache 2.0.