Approaches for resolving dynamic IP addressing

Knowledge of the Internet Protocol (IP) address is essential for connection establishment in certain classes of synchronous distributed applications such as Internet telephony and videoconferencing systems. A problem of dynamic IP addressing arises when the connection to the Internet is through an Internet Service Provider since the IP address is dynamically allocated only at connection time. This paper proposes and contrast a number of generic methods that can be classified as online and off-line methods for the resolution of dynamic IP addressing. On-line methods, which include the World-Wide-Web, exchange server and dynamic Domain Name System, are only effective when both the caller and recipient are logged onto the Internet. On the other hand, off-line methods, which include electronic mailing and directory service lookup, provide an additional means to allow the caller to leave messages when the recipient is not logged onto the Internet. Of these methods, the dynamic Domain Name System and directory service lookup appear best for resolving dynamic IP addressing respectively.