Читать книгу Software Networks - Guy Pujolle - Страница 31

The northbound interface between the application plane and controller passes information pertaining to the applications’ needs so that the controller can open up the best possible software network with the appropriate qualities of service, adequate security and the essential management for the operations to be able to be carried with no problems. The basic protocol for these transmissions is based on the REST (Representative State Transfer) API. This application interface must enable us to send the information necessary for the configuration, the operations and the measurement report. We find this protocol, based on RESTful, integrated into numerous Cloud management systems, and in particular, in the interfaces of most of these systems, such as:

 – OpenStack, in which the REST API is integrated;

 – those of the service providers;

 – the API Virtual Private Cloud (VPC).

The representations facilitated by the REST protocol enable us to pass the information over the northbound interface with the following properties:

 – each resource is identified individually;

 – the resources can be manipulated by representations;

 – the messages are self-descriptive: they explain their nature by themselves;

 – each access to the subsequent states of the application is described in the present message.