%% You should probably cite draft-ietf-sipping-sec-flows instead of this I-D.
@techreport{jennings-sip-sec-flows-03,
    number =    {draft-jennings-sip-sec-flows-03},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-jennings-sip-sec-flows/03/},
    author =    {Cullen Fluffy Jennings and Kumiko Ono},
    title =     {{Example call flows using SIP security mechanisms}},
    pagetotal = 46,
    year =      2005,
    month =     jul,
    day =       18,
    abstract =  {This document shows call flows demonstrating the use of SIPS, TLS, and S/MIME in SIP. This draft provides information that helps implementers build interoperable SIP software. It is purely informational. To help facilitate interoperability testing, it includes certificates used in the example call flows and a CA certificate to create certificates for testing. This work is being discussed on the sip@ietf.org mailing list.},
}