2.1.1 G-Port Message Handling

This procedure describes how G-Port handles a message.

1. The message arrives at vSTP route-on-gt. vSTP decodes the SCCP portion and uses the data to perform G-Port Selection based on the CdPA GT fields other than the ES and GTAI. The result of this selection provides service indicator. The service indicator is G-Port if MNP-SRF is required. If a service selector does not match the incoming GT fields, then GTT selection is attempted.
2. If step 1 indicates MNP-SRF is required and the message is not a UDTS generated by vSTP, vSTP then performs SSN-based discrimination. If the message is a UDTS generated by the vSTP, then regular GTT is performed on the message.
3. MNP-SRF first decodes the Operation Code of the MAP message to distinguish SRI/SRI_SM message from the rest. If the Operation Code is SRI and the OR Interrogation indicator is absent, and the VstpMnpOptions:SRIDN = “TCAP”, then the MSISDN parameter is decoded from the MAP portion of the message. If the Operation Code is SRI_SM, and the VstpMnpOptions parameter SRISMDN = “TCAP”, then the MSISDN parameter is decoded from the MAP portion of the message. If the VstpMnpOptions parameter SRIDN (for SRI message) / SRISMDN (for SRI_SM message) = “SCCP”, or if the message is not SRI or not SRI_SM, then digits available in the SCCP CdPA GTAI are used for the database lookup.
4. The decoded DN (either from MAP MSISDN or from SCCP CdPA) is conditioned to an international number before performing the UDR NPDB lookup. The conditioning is different based on whether the digits are obtained from TCAP or MAP part of the message.
   • If the digits are from the SCCP part, then number conditioning is based on SNAI value. RN prefix deletion is performed first and then converted to international based on its value. Conversion to international format is based on DefCC and DefNDC, as required. If the incoming number is CCRNDN, DefCC and MultCC is used to determine the Best Match CC to locate the RN digits for RN prefix deletion.
   • If the digits are from the MAP part, then number conditioning is based on NAI of MSISDN parameter. Home RN prefix deletion is performed if VstpMnpOptions:MNPCRP is ON. The number is converted to international, if needed. Conversion to international format is based on DefCC and DefNDC, as required. If the incoming number is international, DefCC and MultCC is used to determine if the format is CCRNDN or RNIDN. If a Best Match CC is located, then it is used to locate the RN digits for RN prefix deletion.
5. The UDR NPDB database lookup involves:
   • The exception or individual number database is searched for a match. If the match is found, then the data associated with this entry is considered.
   • If the conditioned number is absent in the exception (individual) database, then the number range database is searched. If the match is found, then the data associated with this range entry is considered. If the search is unsuccessful, then the result is no match.
6. If the number is found, and a RN prefix is present for this entry, then:
   • If the message is SRI, and VstpMnpOptions:MNPCRP is OFF, or if VstpMnpOptions:MNPCRP is ON and a HomeRN was not present in the incoming DN (for example, a HomeRN was not deleted from the SCCP CdPA/MAP MSISDN), then G-Port generates an SRI Ack message with the RN prefix in the RN parameter.
   • If the message is non-SRI, and VstpMnpOptions:MNPCRP is OFF, or if VstpMnpOptions:MNPCRP is ON and a HomeRN was not present in the incoming DN (for example, a HomeRN was not deleted from the SCCP CdPA), then G-Port uses the translation data for the number to alter the CdPA digits and route the message to the destination.
   • If the message is SRI or non-SRI, and VstpMnpOptions:MNPCRP is ON, and a HomeRN was present in the incoming DN (for example, a HomeRN was deleted from the SCCP CdPA/MAP MSISDN), then G-Port generates Event #70304 and the message falls through to the GTT. In most network implementations, since the message contains RN+DN, this should cause a GTT failure, which results in vSTP sending a UDTS to the originator if the return message on error flag was set in the incoming UDT.
   • If VstpMnpOptions:SRISMGTTRTG is ON, then the SRI_SM and ReportSMDeliveryStatus messages is not relayed. Instead, the CdPA GTA in the message is modified in CC+RN+DN format (or RN+IDN format if CC match is not found in leading digits). The NAI of CdPA GTA is set to international and the message falls through to the GTT.
7. If the number is found and an SP entity is present for this entry, then G-Port uses the SP translation data for the number to route the message to the destination. This is true whether or not the VstpMnpOptions:MNPCRP option is ON. However, if GRN is also associated (along with SP entity) with the DN and the GRN is not present in the HomeRN table and VstpMnpOptions:SRISMGTTRTG is ON, then the SRI_SM and ReportSMDeliveryStatus messages are not relayed. Instead, the CdPA GTA in the message is modified in CC+GRN+DN format (or GRN+IDN format if the CC match is not found in leading digits). The NAI of CdPA GTA is set to international and the message falls through to the GTT.
8. If the number is found and neither SP nor RN data is associated with it (this is a direct routing case with the number not known to be ported or not identified to be ported), then
   • If the message is SRI, and VstpMnpOptions:MNPCRP is OFF, or if VstpMnpOptions:MNPCRP is ON and no HomeRN was present in the incoming DN (for example, a HomeRN was not deleted from the SCCP CdPA/MAP MSISDN), and if the portability type associated with the DN entry is other than 3-35 , then G-Port generates a SRI Ack message with the MSISDN in the RN parameter. If the message is SRI, and VstpMnpOptions:MNPCRP is OFF, or if VstpMnpOptions:MNPCRP is ON and no HomeRN was present in the incoming DN (for example, a HomeRN was not deleted from the SCCP CdPA/MAP MSISDN), and the portability type associated with the DN entry is 3-35, then the SRI falls through to GTT (that is, no SRI Ack message is generated).
   • If NPS parameter is encoded in the SRI Ack message
     • VstpMnpOptions:ENCODENPS=ON and DN is associated with PT =0, 1, 2 (foreign number)
     • VstpMnpOptions:ENCDNPSPTNONE=ON and DN is associated with PT = null (deemed foreign number)
   • If the message is non-SRI, and VstpMnpOptions:MNPCRP is OFF, or if VstpMnpOptions:MNPCRP is ON and no HomeRN was present in the incoming DN (for example, a HomeRN was not deleted from the SCCP CdPA), then the message falls through to the GTT.
   • If the message is SRI or non-SRI, and VstpMnpOptions:MNPCRP is ON, and a HomeRN was present in the incoming DN (for example, a HomeRN was deleted from the SCCP CdPA/MAP MSISDN), then G-Port generates Event #70304 and the message falls through to the GTT. In most network implementations, since the message contains RN+DN, this should cause a GTT failure, which results in vSTP sending a UDTS to the originator if the return message on error flag was set in the incoming UDT.
9. If the number is not found in the UDR NPDB, then the VstpMnpOptions:SRIDNNOTFOUND option is consulted if query is not SRI prepaid. If the query is identified to be an SRI prepaid, then an SRI Ack message is sent back. NPS is encoded in the SRI Ack message if VstpMnpOptions:ENCDNPSDNNOTFOUND is ON.
10. If the VstpMnpOptions:SRIDNNOTFOUND option is set to SRINACK, then a negative acknowledgement is generated in response to the given message.
11. If the VstpMnpOptions:SRIDNNOTFOUND option is set to GTT, then GTT is performed on the message.

Figure 2-3 vSTP MNP G-Port Function Flowchart - Sheet 1 of 2

Figure 2-4 vSTP MNP G-Port Function Flowchart - Sheet 2 of 2

Figure 2-5 G-Port Number Conditioning Flowchart

Figure 2-6 G-Port Post-NPDB Lookup Processing Flowchart

Figure 2-7 G-Port MNP CRP Flowchart

Figure 2-8 G-Port CRP on TT Flowchart

Figure 2-9 G-Port SRI Processing Flowchart

Figure 2-10 G-Port Function Flowchart (VstpMnpOptions:SRISMGTTRTG to GMSC)