ALL IP networks in 30 networks support fast growing packet service which is essential to the evolution of 4G networks. Until now, 3GPP has focused on how to replace ATM networks with IP networks but less consideration has been given to how to manage and integrate the legacy IP network and the next generation network for the future. This is a critical problem, since IP RAN is deployed in the IP networks with thousands of network nodes and is expected to be flexible and scalable for the next generation. In this paper, we design and develop an IP RAN management architecture that can be reused for the 3G and 4G network. First, we design a flat management architecture in which an O&M Server manages all of the network elements directly. Second, to manage the thousands of network nodes, O&M Server architecture is proposed as distributed management architecture. Next, RAN node architecture enables management of the heterogeneous nodes identically. Lastly, we include an IP configuration phase for the initialization. From the experimental results, we calculate, using a Blade2000 server, the flat architecture's traffic load and CPU load which can cover 700 network nodes for the flat architecture.