%% You should probably cite draft-ietf-sipcore-sip-token-authnz instead of this I-D.
@techreport{ietf-sipcore-sip-authn-01,
    number =    {draft-ietf-sipcore-sip-authn-01},
    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-sipcore-sip-authn/01/},
    author =    {Rifaat Shekh-Yusef and Christer Holmberg and Victor Pascual},
    title =     {{Third-Party Authentication for Session Initiation Protocol (SIP)}},
    pagetotal = 16,
    year =      2017,
    month =     sep,
    day =       26,
    abstract =  {This document defines an authentication mechanism for SIP, that is based on the OAuth 2.0 and OpenID Connect Core 1.0 specifications, to enable the delegation of the user authentication to a dedicated third-party IdP entity that is separate from the SIP network elements that provide the SIP service.},
}