Network automation with network virtualization is key to SDN and NFV technologies. It is expected to reduce costs and speed up the delivery of network-based services by abstracting configuration information for network services from the physical infrastructure. Thus services may be set up with automated software orchestration tools.
As server virtualization did for computing resources, network virtualization enables hardware resources to be split up and controlled by software. This way, network resources can be configured and divided for different customers and services without requiring physical changes or discrete infrastructures.
Automation and Virtualization
Network automation with network virtualization enables automation by programmatically configuring and provisioning network connections. This is a process known as orchestration. For example, a virtual private network (VPN) could be established by a software controller that orchestrates the compute resources and network hardware needed to provide the service.
Network services are generally programmed using network interfaces and application programming interfaces (APIs) governed by open standards. Using software-defined networking (SDN) and network functions virtualization (NFV) technology, services can be configured or changed based on sets of business or services rules. This defines how the hardware platforms interoperate with each other and enables them to be controlled with software.
Orchestration and Management Tools
The trend toward network virtualization has created a new crop of provisioning and management technology, including for cloud network connections, service provider networks, and wide-area networks (WANs).
The primary goal of using network virtualization to automate the network is to remove the need for humans to manually configure pieces of hardware, which in the past has been done by manually typing in configuration information into a command-line interface (CLI) for a hardware device. One way to imagine it is that instead of physically ordering that money be moved by filling out a form in a branch office of a bank, you could just electronically transfer that money to your bank by clicking a button. Network services can also be automatically configured – without the paperwork.
The SDN and NFV movements are building standards so that network configuration and provisioning can be executed with standard software tools and APIs. There are many different standards, APIs, and open source projects emerging to enable the accomplishment of network automation through virtualization.
One standards area includes the European Telecommunications Standards Institute (ETSI) Industry Specification Group (ISG) for NFV Management and Orchestration (MANO) – the ETSI NFV MANO architecture. This is a defined framework for the management and orchestration of all resources in a cloud data center. ETSI NFV MANO includes specific standards for setting up (orchestrating) network services on cloud servers. The data centers host the services using virtualization technology from commercial vendors such as VMware or open source projects such as OpenStack. OpenFlow is an open source protocol for routing packets through a network to access cloud servers.
Other standards and data models are designed to enable automation across SDN and NFV networks. These include Topology and Orchestration Specification for Cloud Applications (TOSCA) – a standard language to describe a topology of cloud-based Web services, components, relationships, and the processes that manage them. YANG (RFC 6020) is a data modeling language developed by the Internet Engineering Task Force (IETF) for configuration and network state information using NETCONF protocol (RFC 6241).
All of these standards and data models can be thought of as a language for SDN or NFV platforms to talk to one another and order provisioning of services without requiring a manual setup – lowering costs and hastening the delivery of new services.