1. Configuration Guide
  2. SIP Signaling Services
  3. Diversion Info and History-Info Header Mapping

Diversion Info and History-Info Header Mapping

History-Info and Diversion are two headers commonly used in SIP signaling to convey information related to call transfer and call diversion. The Oracle® Enterprise Session Border Controller (ESBC) supports mapping and interworking between networks that support the History-Info versus the Diversion header. You implement this interworking on the ESBC using the diversion-info-mapping-mode parameter on egress sip-interface configuration elements. This interworking, and the subsequent header behaviors, comply with RFC 7544. When configured, the ESBC monitors signaling for the presence of History-info headers that comply with RFC 7044 and Diversion headers that comply with RFC 5806 to trigger the interworking. The ESBC also provides support for RFC 8119, with respect to the cause URI parameter.

The History-Info header is the standard solution adopted by the Internet Engineering Task Force (IETF) for storing re-targeting information. The non-standard Diversion header is also used in many existing network implementations. Individual networks typically use one or the other. As both headers address call forwarding needs but have different syntaxes, having both present in a signaling request can cause diverting information to be misinterpreted, thereby making an interworking solution necessary. In addition to using different syntaxes, these methods also use different reason codes for the diversions, different security flags, and list events using opposite chronology. The diversion header lists the last diversion first; the History-Info header lists the first diversion first.

The ESBC applies the configuration at the egress interface. You can configure the following header interworking modes:

  • Diversion to History-Info
  • History-info to Diversion
  • A combination of Diversion to History-Info interworking and a forced insertion of the History-info header if the INVITE contains neither

When interworking from a History-Info header to a Diversion header, the ESBC initializes the new Diversion header with the value of the History-Info header.