Knowledge of performance measurement tools, systems testing and diagnostics, COTS products, Internet technologies, analytical methods and practices, requirements analysis techniques in order to: test and optimize the functionality of the systems, networks, and data; provide advice on a wide range of IT issues; ensure optimal use of commercially available products; represent the organization in interactions with other organizations; prepare and present reports; conduct analyses and recommend resolution of difficult issues; identify and define business requirements applied to the development, implementation management and support of systems and networks; etc. Knowledge of IT security principles and products; DOD and agency policies, procedures, regulations, directives, and requirements related to physical, personnel, emanations, and information security; methods for evaluating risk or vulnerability; IT INFOSEC security requirements for certification and accreditation; network operations and protocols; systems testing and evaluation, and performance management methods sufficient to plan and conduct security accreditation reviews for installed systems or networks and assess and advise on new or revised security measures and countermeasures based on the results of accreditation reviews.