2.2.2.1 SIP URI Parameter Extensions for Record-Route, Path, and Route Header Fields

  • Article

The following SIP URI parameter extensions can be used in URIs inserted by SIP proxies into the Record-Route header fields of any message described in [RFC3261] section 16, or into the Path header field of the REGISTER request described in [RFC3327] section 5.

  • ms-opaque-param

  • ms-route-sig-param

  • ms-key-info-param

  • ms-identity-param

  • ms-fe-param

  • ms-role-rs-to-param

  • ms-role-rs-from-param

  • ms-ent-dest-param

These extensions can then appear in the Route header field. As specified in [RFC3261] section 12, the list of URIs in the Record-Route header fields, taken in order with all URI parameters, is stored in the dialog state. This list of URIs is also stored in the Route header fields of every SIP request in the SIP dialog. Additionally, as specified in [RFC3327] section 5, the content of the Path header fields is stored by the registrar and then used by the SIP proxy that is responsible for the domain of the request destination to populate Route header fields.