1. Virtual Signaling Transfer Point User Guide
  2. vSTP Features
  3. vSTP AINPQ/INPQ Feature
  4. INP/AINPQ Message Protocol

2.16.2 INP/AINPQ Message Protocol

INP/AINPQ support UDT SCCP messages and non-segmented XUDT messages.

INP and AINPQ support Rt-on-SSN and Rt-on GT messages.

For Rt-on GT, GTA digits must be present. INP and AINPQ support two TCAP protocols: INAP (for the INP feature) and ANSI-41 (for the AINPQ feature). The effective processing of the messages is the same for INAP and ANSI-41 protocols.

The functions are performed in following steps:
  1. For INP, the leading digits of the CdPN number from the INAP portion of the message are compared to provisioned prefixes. If matching prefix digits are found, INP strips the prefix from the CdPN digits.

    For AINPQ, the leading digits of the Dialed Digits from the TCAP portion of the message are compared to any provisioned prefixes (dialpfx). If found, the prefix is stripped from the Dialed Digits.

  2. If an NEC is provisioned and an NEC is present in the CdPN or dialled digits, it is stripped off.
  3. Any stop digits that are present in the CdPN or dialled digits are removed.
  4. For INP, after removing the prefix and NEC, INP maps the CdPN NAI to the Service NAI by doing a lookup in the MnpOptions table. If the CdPN NAI is found in the MnpOptions table, its corresponding SNAI value is used for number conditioning. Otherwise, INP treats the number as national (natl), unless the NAI field in the CdPN is subscriber (sub) or international (intl).

    For AINPQ, after removing the prefix, ST digits, and NEC from the Dialed Digits, the NAI is mapped to the Service NAI from the AINPOPTS table, and the corresponding SNAI value is used for number conditioning. If mapping is not found, AINPQ treats the number as National, unless the NAI field in the Dialed Digits is Subscriber or International.

  5. If the INP Circular Route Prevention feature is turned on, the RN is matched with the Home RNs in the HomeEntity table. The Home RN that matches with the maximum number of leading digits of the CdPN is removed from the CdPN.