1. Diameter Signaling Router Mobile Number Portability User Guide
  2. vSTP G-Flex Feature
  3. G-Flex Relay Function Description
  4. Conversion of E.214 MGT to E.212 IMSI

Conversion of E.214 MGT to E.212 IMSI

Because the GDB does not store MGTs, the messages with E.214 MGT in the CdPA GTAI are converted to an E.212 International IMSI in order to perform the GDB lookup. G-Flex maintains a logical MGT2IMSI conversion table to perform this conversion. The MGT2IMSI conversion table contains up to ten entries of E.164 part (CC + NC digits) and its corresponding E.212 part (MCC + MNC). If a G-Flex message has E.214 as the CdPA numbering plan, G-Flex Relay performs the following steps to derive the E.212 International IMSI:

  1. G-Flex Relay uses MGT as the key and does a lookup in the MGT2IMSI conversion table to find a match on E.164 part (CC + NC digits).

  2. If a match is found, G-Flex Relay replaces the matched digits of the MGT with the corresponding E.212 part (MCC + MNC digits). If a match is not found, a measurement is issued and the G-Flex Relay falls through to GTT.

  3. G-Flex Relay uses this complete E.212 International IMSI number to do the GDB lookup.

Note:

If the IMSI for a particular country/network is the complete 15 digits and the E.164 CC + NC for that country is more than five digits, the MGT generated could contain a truncated MSIN. This is possible because the converted MGT is more than 15 digits and the maximum number of digits allowed in the MGT is 15 digits. (Refer to E.214 for more details on conversion.) Under these circumstances, the MGT is truncated at 15 digits. Therefore, the MGT-to-IMSI reconversion would not regenerate a complete IMSI and would lead to incorrect results and errors.