%% You should probably cite draft-ietf-sipping-3pcc instead of this I-D.
@techreport{rosenberg-sip-3pcc-03,
    number =    {draft-rosenberg-sip-3pcc-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-rosenberg-sip-3pcc/03/},
    author =    {Jonathan Rosenberg and Henning Schulzrinne and Gonzalo Camarillo},
    title =     {{Third Party Call Control in SIP}},
    pagetotal = 22,
    year =      2001,
    month =     nov,
    day =       29,
    abstract =  {This document discusses the usage of the Session Initiation Protocol (SIP) for third party call control. Third party call control refers to the ability of one entity to create a call in which communications is actually between other parties. We present a SIP mechanism for accomplishing third party call control that does not require any extensions or changes to SIP.},
}