Hannes Tschofenig Henning Schulzrinne Murugaraj Shanmugam Andrew Newton Protecting First-Level Responder Resources in an IP-based Emergency Services Architecture. 626-631 2007 IPCCC http://dx.doi.org/10.1109/PCCC.2007.358952 conf/ipccc/2007 db/conf/ipccc/ipccc2007.html#TschofenigSSN07