Topology and Orchestration Specification for Cloud Applications (TOSCA) is a data model standard managed by industry group OASIS that can be used to orchestrate network functions virtualization (NFV) services and applications. TOSCA does this by using its information model and templates to coordinate, or orchestrate, the setup application services with NFV hardware in the cloud.
Because one if TOSCA’s strength is to orchestrate services, it can be integrated with other NFV orchestration technology and tools including those that are compatible with the ETSI management and orchestration (MANO) standards for NFV. Telecom companies, enterprises, and cloud operators are looking to open standards such as TOSCA and the MANO architecture to set up open, portable cloud services.
The TOSCA Data Model
Typically referred to as a modeling language, TOSCA is often grouped with other data modeling standards and protocols such as the IETF’s YANG and Netconf, though these sets of standards all have different capabilities. TOSCA can deliver a declarative description of the application topology for a network or cloud environment that includes all its components, which may include the need for load balancing, networking, computing resources, and other software. It can also be used to define the workflows that need to be automated in a virtualized environment. TOSCA enthusiasts believe this can simplify the configuration of networking elements and end-to-end lifecycle service orchestration (LSO) of NFV and other cloud services.
The TOSCA modeling language includes concepts such as nodes and relationships, whereby a node is an infrastructure such as a network, subnet, or a server software component. TOSCA can help define how these nodes and services work together. TOSCA uses templates to automate the configuration of these relationships.
TOSCA NFV and MANO
One of the advantages of NFV is that uses standardized hardware to deploy services and applications. These services can be installed as software on top of a standard hardware platform, which allows more flexibility and adaptability. These applications are known as virtual network functions (VNFs).
In a TOSCA NFV environment, TOSCA works together with the NFV MANO components to orchestrate and automate cloud infrastructure and resources. MANO definitions include the VIM (Virtual Infrastructure Manager), which controls the interaction of the VNF with the compute, networking and storage resources of the chosen NFVI (i.e. cloud or virtualization layer); the VNFM (Virtual Network Function Manager), which responsible for the VNF lifecycle management, and the NFV orchestrator, which coordinates and manages the software and infrastructure resources of the VIM, and realizing the NFV infrastructures (NFVI’s) network services.
Typically, TOSCA is used with NFV MANO components – most often orchestrators — which are often marketed as either open source or software packages offered by vendors. Some open source projects that can integrate with TOSCA include Open-O , OPNFV, and the OpenStack Neutron project. A few of the prominent software vendors that implement TOSCA include CA, Cloudify, IBM, and Red Hat, VMware – to name a few. Ciena, Cisco, Nokia, and ADVA are some of the many vendors on the networking side that have embraced TOSCA NFV environments. Dozens of vendors support TOSCA. Many supporters of OASIS TM can be found here.
The use of TOSCA along with MANO, YANG/Netconf, and other standards will be important in NFV adoption to help deliver orchestration and interoperability of services. TOSCA helps define topologies, dependencies, and relationships between virtual applications and can simplify the complexities of of these services.