G-Flex MAP Layer Routing
The vSTP G-Flex feature can perform GDB subscriber number lookup based either on a subscriber’s E.164 MSISDN number, or the subscriber’s E.212 IMSI number. In some GSM networks, MSCs use an E.214 MGT (Mobile Global Title) number for routing between networks. G-Flex cannot perform database lookup directly with an E.214 MGT number, but it can convert the E.214 MGT into a E.212 IMSI number, and thus correctly process the message. In an ITU network, when a visited network entity (VLR, GGSN, SGSN, or GMLC) needs to contact a home network entity ( AuC or HLR) given only the IMSI of a subscriber, it will convert the E.212 IMSI into an E.214 MGT. This process applies only to the first message of a dialogue. Subsequent messages of that same dialogue will be routed using E.164 numbers.
When the SCCP CdPA is truncated by the MSC in a message that is received for G-Flex service, G-Flex needs to use the subscriber number from the MAP layer for routing.
The G-Flex MLR feature supports G-Flex routing for messages based on the MAP-layer IMSI and MSISDN parameters that does not involve checking the format of the CdPA , though the messages contain SCCP Called Party Address (CdPA) parameters in ITU E.214 format. The CdPA should contain an E.214 number, but its format and content have no bearing on the G-Flex MLR function.
G-Flex MLR processes messages with the MAP operations shown in the following table:
Table 6-5 MAP Operations Processed by G-Flex MLR
MAP Operation Name | Processing |
---|---|
updateLocation | G-Flex MLR processes messages with MAP operations that commonly encode the SCCP CdPA GTA in the E.214 format (MGT) where trailing IMSI digits may be truncated from the MGT, and that always include IMSI in the MAP layer. |
updateGprsLocation | |
sendParameters | |
sendAuthenicationInfo | |
registerSS | |
activateSS | |
deactivateSS | |
interrogateSS | |
authenticationFailureReport | |
restoreData | |
readyForSM | |
purgeMS | |
processUnstructuredSS-Request | G-Flex MLR processes messages with MAP operations that include either an IMSI or an MSISDN in the TCAP component. |
sendRoutingInfoForLCS | |
AnyTimeInterrogation | G-Flex MLR processes messages with the AnyTimeInterrogation (ATI) operation, using the MSISDN from the MAP layer of the ATI message for conditioning and GDB look up. The MSISDN is converted to International format for GDB searching based on the Nature of Address Indicator in the MAP MSISDN parameter. No HomeRN deletion is required. |
The Application Context Name and version supported by G-Flex MLR are shown in the following table:
Table 6-6 MAP Protocol Versions Supported by G-Flex MLR
MAP Operation | MAP Operation Name | Application Context Name and Version Supported | IMSI from Component or Dialogue Portion of TCAP | Lookup for MSISDN if IMSI is Missing | MSISDN from Component or Dialogue Portion of TCAP |
---|---|---|---|---|---|
Location Update (2) | updateLocation | networkLocUpContext-v3
application-context-name value of 0.4.0.0.1.0.1.3 |
Component | No | NA |
networkLocUpContext-v2
application-context-name value of 0.4.0.0.1.0.1.2. |
|||||
networkLocUpContext-v1 | |||||
Send Parameters (9) | sendParameters | infoRetrievalContext-v1 | Component | No | NA |
Update GPRS Location (23) | updateGprsLocation | gprsLocationUpdateContext-v3
application-context-name value of 0.4.0.0.1.0.32. |
Component | No | NA |
Send Authentication Information (56) | sendAuthenticationInfo | infoRetrievalContext-v3
application-context-name value of 0.4.0.0.1.0.14.3. |
Component | No | NA |
infoRetrievalContext-v2
application-context-name value of 0.4.0.0.1.0.14.2. |
|||||
AnyTime Interrogation (71) | AnyTimeInterrogation | anyTimeInfoEnquiryContext-v3
application-context-name value of 0.4.0.0.1.0.29.3. |
NA | Yes (MSISDN is only looked up) | Component |
Register Supplementary Service (10) | registerSS | networkFunctionalSsContext-v2 | Dialogue | No | NA |
Activate Supplementary Service (12) | activateSS | networkFunctionalSsContext-v2 | Dialogue | No | NA |
Deactivate Supplementary Service (13) | deactivateSS | networkFunctionalSsContext-v2 | Dialogue | No | NA |
Interrogate Supplementary Service (14) | interrogateSS | networkFunctionalSsContext-v2 | Dialogue | No | NA |
Authentication Failure Report (15) | authenticationFailureReport | authenticationFailureReportContext-v3 | Component | No | NA |
Restore Data (57) | restoreData | networkLocUpContext-v3
networkLocUpContext-v2 |
Component | No | NA |
Process Unstructured SS Request (59) | processUnstructuredSS-Request | networkUnstructuredSsContext-v2 | Dialogue | Yes | Dialogue |
Ready For Short Message (66) | readyForSM | mwdMngtContext-v3
mwdMngtContext-v2 |
Component | No | NA |
Purge Mobile Subscriber (67) | purgeMS | msPurgingContext-v3
msPurgingContext-v2 |
Component | No | NA |
Send Routing Information for Location Service (85) | sendRoutingInfoForLCS | locationSvcGatewayContext-v3 | Component | Yes | Component |
- MAP Update_Location
- Update_GPRS_Location
- Send_Parameters
- MAP Send_Authentication_Information
G-Flex MLR also processes messages with the AnyTimeInterrogation (ATI) operation, using the MSISDN from the MAP layer of the ATI message for conditioning and GDB look up. The MSISDN is converted to International format for GDB searching based on the Nature of Address Indicator in the MAP MSISDN parameter. No HomeRN deletion is required.
- updateLocation
- updateGprsLocation
- sendParameters
- sendAuthenicationInfo
- AnyTimeInterrogation
-
NONE - The G-Flex MLR function is not performed for a message that contains an updateLocation, sendParameters, sendAuthenticationInfo, updateGprsLocation, or AnyTimeInterrogation operation code. Normal G-Flex processing is applied to the message. The IMSI or MSISDN is taken from the SCCP CdPA parameter for TC-BEGIN messages.
-
IMSI - The G-Flex MLR function uses the IMSI for the GDB lookup, for the updateLocation, sendParameters, sendAuthenticationInfo, and updateGprsLocation operations.
-
MSISDN - The G-Flex MLR function uses the MSISDN for the GDB lookup, for the AnyTimeInterrogation operation.
-
All - The G-Flex MLR function uses the IMSI or the MSISDN for the GDB lookup, based on the operation code of the message. If the message contains an updateLocation, sendParameters, sendAuthenticationInfo, or updateGprsLocation operation code, the G-Flex MLR function uses the IMSI parameter. If the message contains an AnyTimeInterrogation operation code, the G-Flex MLR function uses the MSISDN parameter.
For the operations shown in unresolvable-reference.html#GUID-15AB2E5F-E2F6-4AA6-A0C0-77CF3BCE5404__V3934633, G-Flex MLR uses the GSMOPTS MAPLYRRTGON configuration option to turn on processing of each specified operation or all operations, and the MAPLYRRTGOFF configuration option to turn off processing of each specified operation or all operations. The values are specified in a comma-separated list for the option in the chg-gsmopts
command. One or both options can be specified in one command, but the same value cannot be specified in both options in the same command. When ALL is specified for one option, the other option cannot be specified in the same command.
Table 6-7 GSMOPTS Configuration Options MAPLYRRTGON and MAPLYRRTGOFF
Operation Name | Configuration Option Value |
---|---|
registerSS | regss |
activateSS | actss |
deactivateSS | dactss |
interrogateSS | intross |
authenticationFailureReport | authfailrpt |
restoreData | rstdata |
processUnstructuredSS-Request | procunstrqt |
readyForSM | rdyforsm |
purgeMS | purgmobss |
sendRoutingInfoForLCS | sriloc |
All 10 operations listed in this table | all |
- The G-Flex MLR feature is not turned on.
- The received message does not include an operation of interest.
- The operation does not contain an IMSI parameter.
- The operation does not contain an MSISDN parameter. No measurement is generated.
- The G-Flex MLR feature encounters a supported operation code that contains an invalid ACN.
- The G-Flex MLR feature is enabled and turned on.
- An incoming MSU contains and SCCP UDT message type code or XUDT non-segmented message type code.
- The message contains a TCAP Message Type of Begin (in the MAP layer information of only the first TCAP component of the message).
- The TCAP component is Invoke.
- The GSMOPTS GFLEXMAPLAYERRTG configuration option is not NONE.
- For the message processing controlled by the GSMOPTS GFLEXMAPLAYERRTG configuration option, the option is not NONE.
- For the message processing controlled by the MAPLYRRTGON option, the option must be set for the operation code in the incoming message, and
-
SCCP CdPA NP=E.214 if CdPA GTI=4 and NP is present.
-
The length of the MCC+MNC (Mobile Country Code + Mobile Network Code) in the resulting E.212 IMSI number must be greater than the length of the CC+NDC (Country Code+Network Destination Code) in the E214 MGT number that is converted to the E212 IMSI number. The maximum length of the SCCP CdPA is 15 digits.
If the MCC+MNC length is greater than the CC+NDC length and CdPA is 15 digits, then after E.214 MGT to E.212 IMSI conversion, the resulting number of digits is greater than 15. The last digits may be truncated; in this case IMSI digits can be taken from the MAP layer.
-
SCCP CdPA GTI=2
- The SCCP CdPA GTA length is not checked because the SCCP CdPA Encoding Scheme (ODD or EVEN) is not known in this case, and there might be filler digits ('0') that make the length determination uncertain.
or
The CdPA GTI=4 and the SCCP CdPA length is 15 digits.- If the length of the SCCP CdPA GTA is 16 digits and the last digit is a stop digit ('0xF'), the stop digit is treated as a filler digit and the CdPA GTA length is considered to be 15 digits.
- If the CdPA GTI=4, the SCCP CdPA GTA is 8 bytes, and the Encoding Scheme is not BCD ODD (1) or BCD EVEN (2), the Encoding Scheme is assumed to be BCD EVEN (2).
-
- Missing IMSI (a measurement is not generated for a missing MSISDN)
- Decoding errors such as an IMSI parameter value that does not have at least 5 digits and no more than 15 digits, or an MSISDN parameter value that does not have at least 1 digit and no more than 15 digits
- MSISDN digits with the NAI set to Subscriber or National and the STPOPTS Default Country Code (DEFCC) or Default Network Destination Code (DEFNDC) configuration option is not set appropriately
- Invalid TCAP component
G-Flex MLR affects only the selection of digits for GDB lookup. All other processing is the same as G-Flex. No changes are made to the MAP layer of the outgoing message; the SCCP layer may be changed per the provisioned Network Entity parameters in the EPAP (such as Digit Action).