Introduction

Introduction

Network function virtualization (NFV) is a network architecture concept which tries to substitute the hardware devices using software in a virtual machine. That allows multiple network functions in a same server, for instance; routers, switches, firewalls... If all of them were virtualized, they could be run in the same computer.

Virtualized network functions are composed by entities which can be either minimum element or formed by the union of multiple entities. For example, the minimal unit are de virtual deployment units (VDU) which are contained in other subset of entities called virtual network function (VNF), at the same time, a set of VNF can form a superior entity called network service (NS).

The function of the validator

Every virtualized network function is represented by a file called descriptor which contains all information about the funcion. In SONATA, the descriptors are written in YAML format and every descriptor must follow a particular schema. There are schemas for VNF, NS... (more information in schemas section). The descriptor names are defined adding 'descriptor' at the end of the name of the function, for instance, virtual network function descriptor (VNFD), network service descriptor (NSD), etc.

The descriptors are created by the user and it is possible that they have some problem, so it is necessary to check all the parts of them are correct. This is the function of the validator, checking all the fields of the descriptor searching either errors or some parts which can cause problems.

The validator implements four validation levels: syntax, integrity, topology and custom rules. This levels can be used to check the correct form of the descriptors, if there are either errors or warnings, the validator will show them to allow the user corrects them.

Use tng-sdk-validate -h to see more options.