It has to be assured, that people in distress - when placing an emergency call - are routed to the best control center within best possible accuracy and highest reliability. The necessity of information transmission during life threatening situations and therefore also the location of the place of emergency or the most efficient dispatching of resources demands the expansion of given standards. Nowadays, telecom-providers are delivering emergency calls via legacy networks only. Those conventional method in delivery actually produce a lack of consistency of data while delivering those datagram's from legacy networks to IP-networks. This book deals with the analysis of the therefore given discrepancy and additionally will bring up a solution for actual problems. The solution (transmission of relevant data and handling of emergency calls within IP-networks) will be presented as the Legacy Network Gateway (LNG). The solution part includes an analysis of necessary features and the theoretical assembly of those functional blocks after showing the different conclusions and the overall description of a fully functional LNG and its scope of work.