Wireless local-area networks (WLANs) based on the IEEE 802.11 technology have been widely adopted for private use over the past few years. However, several issues remain concerns for large-scale deployment in corporate environments. Enforcing security and quality-of-service (QoS) has become a fundamental challenge to managing IEEE 802.11-based enterprise networks. In order to provide corporate networks with a global management solution, we have designed a service-oriented management system that enables user-centric service provisioning, while enforcing security and QoS requirements. As enterprises may be comprised of a number of distinct networks, we have extended our system to support the roaming of users between different enterprise sites. In this paper, we describe the design, implementation, and performance evaluation of our solution.