Interworking ANM or CON with History-Info Headers

This interworking applies to SIP-I to SIP calls. If the 200OK message from the SIP side contains one or more history-info headers and you have set the redirection mode on the egress side to history-info, the SBC populates these parameters into the ANM/CON message.

When configured for native IWF and in receipt of History-Info information, the SBC interworks the following parameter groups:

• Redirection Number
• Redirection Number Restriction

Redirection Number

The SBC only adds this parameter for ANM messages. Redirection Number subfield interworking includes:

• Nature of address indicator—The SBC inserts the following values, based on the conditions described:

  • National, if there is no + in the number (encoded to 0000011).
  • International, if there is a + in the number (encoded to 0000100).
• Internal Network Number Indicator—The SBC always inserts the value routing to internal network number not allowed (1).
• Numbering Plan Indicator—The SBC always inserts the value ISDN (001).
• Address Signal—The SBC inserts URI of the last History-info header with a cause parameter.

Redirection Number Restriction

The APRI is the only parameter interworked for this category:

• If the SIP Privacy or the priv-value component in the History-info entry containing a cause URI parameter is set to History, Session, or Header map the APRI to presentation restricted (01).
• If both the Privacy header or priv-value component in the last History-info header containing a "cause" URI parameter are absent or have any other value, map to presentation allowed (00).

Per the standard, the priv-value component in the history-info header can only have a value of either "history" or "none".