Network Functions Virtualization (NFV) is a recent industrial trend which gains a lot of attention from telecom operators and vendors. The NFV concept delivers network services using commercial off-the-shelf hardware and IT virtualization technologies, thus virtualizing entire classes of network node functions. Traditional and recent data-center architectures are mostly built and optimized for data storage or web based applications. However, NFV type applications have different characteristics with respect to network load and needed computing capacity, which may impact the data-center design. Therefore in this paper, we are motivated to model the characteristics of NFV type applications and investigate the suitability of current data-center architectures for such new applications.