rchestrator can instantiate additional instances of the VNF to cover the increase in traffic. Once the analysis is performed and the other controls kick-in, the additional instances of the VNF can automatically be removed as the demand decreases. 9.3 SECURITY CHALLENGES The deployment of SDN and NFV technologies in networks presents some security challenges in a number of different areas: architecture, technology, and operations. This section focuses on those challenges that are specifically related to SDN and NFV. There are a number of other challenges that are more appropriately considered cloud-deployment challenges. An example would be the ability for traffic to stay within a server and not being subject to some security controls. There are also a number of challenges that are shared with cloud deployments. For example, the existence of more software in the deployed solution-(both cloud infrastructure software, as well as SDN and NFV require more software). This creates a security challenge with the opportunity for bugs or malware to be introduced into the environment. Other examples include the need for new or modified pro- cesses, different data flows, different operations flows, more distinct separation between infrastruc- ture and applications, and the resulting impact and coordination with operations teams. Another shared challenge is that components of the infrastructure may react to stresses differently-what may happen with a particular device or appliance (e.g., fail open); might work differently in the cloud environment than in a SDN and NFV implementation (e.g., fail closed). From an architecture perspective, SDN both centralizes the control and distributes the imple- mentation points for the networking. This provides the ability to provide more coordinated control; however, should the central controller have a security issue, the impact could be dispersed across the entire network. Establishing an architecture and implementation that provides a significant barrier for accessing the SDN controller i