 Let's now look at a scenario where we have an operator and it is connected to an enterprise through the user-to-network interface. Now the operator exposes the virtual network platform as a service to the enterprise. It means now the enterprise would now be able to program the infrastructure to meet certain service requirements. The framework is going to be we have an enterprise that instantiates its own virtual network functions on a network function virtualization infrastructure operated by the service provider. So it means now it's going to be a combination of infrastructure as a service and network as a service capabilities in the virtual network platform. For instance we can think about a data center which is not physically present with an enterprise but it's a virtual data center. Let's look at the details of it through the proper use case definition. So we have the service provider and an enterprise which mutually work together. So what is now going to be programmable? The service provider infrastructure has deployed a network function virtualization infrastructure. This is offered as a platform as a service. It would include capabilities similar to a cloud environment which could possibly provide on-demand connectivity through network as a service infrastructure and provide services to the enterprise. This is the programmable infrastructure. Now the enterprise is now going to create a virtual data center like infrastructure on the service provider's infrastructure. The traditional approach is what we've already discussed. It's mundane because it's going to be between two entities needing a lot of negotiations and if there's something which goes wrong then both of these have to be fully involved in it. But in the programmability based approach the service provider authorizes the enterprise to have access to its own infrastructure as a platform. The virtual network platform includes the networking and computing elements for instance creating virtualized switches, routers, gateways, firewalls, access control lists. The function virtualization infrastructure provides network as a service capabilities to connect dynamically from the enterprise to this infrastructure to be provisioned subsequently to another let's say customer base that the enterprise is offering services to. The network programmability part here in this case would involve the programming of the environment which is secured through authorization and the service provider is the authorized user which would now give access to the enterprise. The network as a service provides on-demand connectivity with authorized access points within the virtualized infrastructure and then we also need a network as a service capabilities. So what are the possible challenges that we would expect? First we already know not all functions could be virtualized then if there is a OSS, BSS specific business flow it has to be taken take into account the virtual network functions based implementation. The skills have to be honed and resharpened for the staff and then the commercial offering for this particular business scenario has to include the service level agreements and the terms and conditions specifically with regards to virtualization. The advantages are going to be again quite attractive that is it's a pooled resource between the enterprise and the service provider primarily the server provider providing services to the enterprise and then this also allows the limited control of abstraction because here we have the overall capital expenditure and operating expenditure which is borne by the two so it means that having a control on the infrastructure enables portability and interoperability developed by the service provider which is provided as is to the enterprise and then last but not the least the service provider actually has to give services to the enterprise to be subsequently leased or provisioned to the end customer in a very agile manner. So it means a large number of customer base could be incorporated without much worry. We are still roaming about in the same at this report and there are various interesting scenarios the report is publicly available you could go and have a look at yourself.