Wireless local-area networks (WLANs) based on IEEE 802.11 technology have been widely constructed for commercial benefit over the past few years. However, several issues remain to be concerned for large-scale deployment in corporate environments. Fundamental challenges of managing IEEE 802.11 based enterprise networks are how to enforce Service Level Agreements (SLAs) and how fairly to utilize the WLANs potential. In order to provide corporate networks with a scalability management solution, we have designed a differentiated service management system that enables service provision and obeys SLAs. As enterprises may be composed of a number of distinct hotspot networks, we extend our system to integrate the network resource allocation among different enterprise sites and effectively to reduce congestion among WLANs. The proposal integrates radio resource allocation and network equipments management with Simple Network Management Protocol (SNMP). In this paper, we describe the design, implementation, and performance evaluation of our solution.