@techreport{ietf-sip-serverfeatures-05,
    number =    {draft-ietf-sip-serverfeatures-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-serverfeatures/05/},
    author =    {Jonathan Rosenberg and Henning Schulzrinne},
    title =     {{The SIP Supported Header}},
    pagetotal = 8,
    year =      2001,
    month =     jul,
    day =       24,
    abstract =  {The Session Initiation Protocol (SIP) provides a mechanism that allows a client to request that a particular protocol extension be used to process the request. The server declines the request if it does not support the extension. However, there is currently no way for a server to determine which extensions are supported by the client. Knowing about client-supported extensions allows the server to tailor its response accordingly. Furthermore, SIP does not define a way for a client to query a server about the extensions it supports. This document defines a SIP extension that allows clients to indicate, in a request, the set of extensions supported. We also define a mechanism that allows clients, through an OPTIONS request, to determine the extensions supported by a server.},
}