Building NS modular bring a lot of benefits.
- Simplifies NS building ; simple small networks built and then composed to make it complex.
- Reduces maintenance overheads.
- Allows reuse ; use the existing the network service.
- Individual NS can be from different companies.
- Can have hierarchy.
The proposal is to define the TOSCA node model for the NS (abstract and substituted service template) which facilitates the modularity , composition and nesting of NS.
- NS can include VNF, PNF and other nested NS along with the SAP if any.
- Nested NS is represented as an abstract node which can have its implementation as another service template or it can be referenced from an existing NS.
The proposal also defines the ETSI NFV compliant SAP node.