A method for creating, modifying, and terminating connections between Internet end systems, particularly, although not exclusively, for Internet telephony communication. The method relies on several request messages sent between a client and a server and the response messages sent back in response. Each request and response message may contain one or more header fields which modify or more uniquely link the messages with a given connection. On this basis, advanced telephony services, such as call forwarding, call transferring, and multiparty conferencing are provided.