@techreport{ietf-sip-call-flows-05,
    number =    {draft-ietf-sip-call-flows-05},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-sip-call-flows/05/},
    author =    {Steve Donovan and Robert Sparks and Dean Willis and Jonathan Rosenberg and Henning Schulzrinne and Chris Cunningham},
    title =     {{SIP Call Flow Examples}},
    pagetotal = 220,
    year =      2001,
    month =     jun,
    day =       28,
    abstract =  {This informational document gives examples of SIP (Session Initiation Protocol) call flows for IP telephony. Elements in these call flows include SIP User Agents and Clients, SIP Proxy and Redirect Servers, and Gateways to the PSTN (Public Switch Telephone Network).},
}