@techreport{schulzrinne-sipping-sos-04,
    number =    {draft-schulzrinne-sipping-sos-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-schulzrinne-sipping-sos/04/},
    author =    {Henning Schulzrinne},
    title =     {{Emergency Services for Internet Telephony based on the Session Initiation Protocol (SIP)}},
    pagetotal = 14,
    year =      2003,
    month =     jan,
    day =       8,
    abstract =  {This document describes how Session Initiation Protocol (SIP) user agents and proxies can set up emergency calls and, more generally, reach emergency assistance via SIP requests. For that purpose, it defines a universal emergency SIP URI, sip:sos@domain and sips:sos@domain, that allows SIP user agents to contact the local emergency number. It also defines conventions that increase the high probability of reaching the appropriate emergency call center. The document does not define any SIP protocol extensions.},
}