In this paper, we study web services methods and approaches to enable real-time communication services over IP. This approach extends web services methodologies from service integration to a serviceoriented approach for communication. In particular, we describe the generic web service based application session management, WS-Session, the two-way full duplex web service interaction framework, and most importantly, the development of Web Service Initiation Protocol (WIP) which is a full featured web service and SOA based communication framework for multimedia and voice communication over IP. We show that WIP provides a service oriented architecture which can be extended seamlessly from a P2P endpoint to an endpoint with advanced call control and switching capabilities typically requiring the assistance of a dedicated PBX. A prototype of WIP system is fully developed. Architectural design and system implementation of web service based communication endpoints are studied and applied to realize service-oriented communication over IP. Advances of WIP indicate the beginning of a full web service and SOA based communication paradigm that can reshape the converged communication over IP.