Determining Host Location on the Internet: The Case of VoIP Emergency Calls

Determining a host's location on the Internet is an important issue in many applications such as the ability for handling emergency services. In this paper we discuss techniques in this area in the context of locating callers to Internet Telephony systems. We mainly discuss two broad groups of these techniques that might fit into VoIP solutions, namely database techniques and measurement based techniques. We also discuss how IPv6 addresses location information. The paper concludes with a discussion on major issues in this important area.