@misc{rfc3608,
    series =    {Request for Comments},
    number =    3608,
    howpublished =  {RFC 3608},
    publisher = {RFC Editor},
    doi =       {10.17487/RFC3608},
    url =       {https://www.rfc-editor.org/info/rfc3608},
    author =    {Bernie Hoeneisen and Dean Willis},
    title =     {{Session Initiation Protocol (SIP) Extension Header Field for Service Route Discovery During Registration}},
    pagetotal = 17,
    year =      2003,
    month =     oct,
    abstract =  {This document defines a Session Initiation Protocol (SIP) extension header field used in conjunction with responses to REGISTER requests to provide a mechanism by which a registrar may inform a registering user agent (UA) of a service route that the UA may use to request outbound services from the registrar's domain.},
}