%% You should probably cite rfc7092 instead of this I-D.
@techreport{ietf-straw-b2bua-taxonomy-01,
    number =    {draft-ietf-straw-b2bua-taxonomy-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-straw-b2bua-taxonomy/01/},
    author =    {Hadriel Kaplan},
    title =     {{A Taxonomy of Session Initiation Protocol (SIP) Back-to-Back User Agents}},
    pagetotal = 9,
    year =      2013,
    month =     feb,
    day =       25,
    abstract =  {In many SIP deployments, SIP entities exist in the SIP signaling path between the originating UAC and final terminating UAS, which go beyond the definition of a Proxy, performing functions not defined in standards-track RFCs. The only term for such devices provided in {[}RFC3261{]} is for a Back-to-Back User Agent (B2BUA), which is defined as the logical concatenation of a User Agent Server (UAS) and User Agent Client (UAC). There are numerous types of SIP Back-to-Back User Agents (B2BUAs), performing different roles in different ways. For Example IP-PBXs, SBCs and Application Servers. This document identifies several common B2BUA roles, in order to provide taxonomy other documents can use and reference.},
}