@techreport{holmberg-ecrit-emergency-callback-id-00,
    number =    {draft-holmberg-ecrit-emergency-callback-id-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-holmberg-ecrit-emergency-callback-id/00/},
    author =    {Christer Holmberg},
    title =     {{Session Initiation Protocol (SIP) emergency call back identification}},
    pagetotal = 12,
    year =      2011,
    month =     oct,
    day =       24,
    abstract =  {This specification define a new type of Globally Routable User Agent URI (GRUU) {[}RFC5627{]}, called emergency GRUU (eGRUU). When a User Agent (UA) provides makes an emergency call, it can provide the eGRUU to a PSAP, which can then use it to make a PSAP callback call. The specification also defines a new URI parameter, "psapcb", which can be used to indicate that a URI can be used for PSAP callback calls. A registrar will provide the URI parameter as part of the generated eGRUU value. Later, when a PSAP makes a PSAP callback call the URI, including the "psapcb" URI parameter, can be used by SIP entities to identity callback calls.},
}