1. Configuration Guide
  2. SIP Signaling Services
  3. SIP SIP-I Interworking
  4. Interworking Call Flows with Diversion Information
  5. Interworking IAM with Diversion Information

Interworking IAM with Diversion Information

When configured properly and in receipt of diversion information, the SBC interworks the following parameter groups in addition to those documented previously:

  • Redirection Number
  • Redirecting Information
  • Original Called Number

For any overlapping interworking, the SBC uses the values in this diversion information list.

Redirection Number

Parameters interworked for this category include:

  • Address Signal—The SBC inserts URI of the selected Diversion header. If there are multiple headers, it uses the first (top).

  • Nature of address—The SBC inserts the following values into the IAM, 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).
  • APRI:
    • If the SIP Privacy value is absent or set to none, map the APRI to presentation allowed.
    • In all other cases, map to presentation restricted.

Redirecting Information

Parameters interworked for this category include:

  • Redirecting Indicator—The SBC uses the following mapping:
    • Privacy header absent or set to none—The SBC inserts the value Call diverted.
    • Privacy header set to any other value—The SBC inserts the value Call diverted, all redirection info presentation restricted.
  • Original Redirection Reason—The SBC always maps this value to Unknown.
  • Redirection Counter—The SBC inserts the sum of the counters of all Diversion headers in the SIP message.

Original Called Number

For Original Called Number, mapping includes:

  • Address Signal—The SBC inserts the URI of the selected History-Info or Diversion header. If there are multiple headers, it uses the last (bottom).

  • Nature of address—The SBC inserts the following values into the IAM, 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).
    • Numbering Plan Indicator—The SBC always inserts the ISDN (Telephony) numbering plan; (Recommendation E.164)
    • APRI:
      • If the SIP Privacy value is absent or set to none, map the APRI to presentation allowed.
      • In all other cases, map to presentation restricted.