Redwood City, Calif. -- Opnet Technologies, a Maryland-based developer of application and network performance management tools, said it has acquired Redwood City-based Clarus Systems, a maker of software designed to improve the service performance and availability of unified communications systems. Financial terms of the deal were not disclosed. Opnet said the acquisition expands its product portfolio for application and network performance management. "There is an innate expectation in enterprises that voice services should be flawless and always available," said Marc Cohen, Opnet's chairman and CEO. "However, when these services are implemented over a converged network, the only way to meet this requirement is with a powerful management solution that is able to comprehensively test, monitor and troubleshoot the entire infrastructure and its configuration… We are excited about expanding our capabilities in this area."