| MCC | 429 | Nepal |
|---|---|---|
| MNC | 01 | Nepal Telecom |
| MSIN | 1234567890 |
| MCC | 310 | USA |
|---|---|---|
| MNC | 150 | AT&T Mobility |
| MSIN | 123456789 |
IMSI analysis is the process of examining a subscriber's IMSI to identify the network the IMSI belongs to, and whether subscribers from that network may use a given network (if they are not local subscribers, this requires a roaming agreement).
If the subscriber is not from the provider's network, the IMSI must be converted to a Global Title, which can then be used for accessing the subscriber's data in the remote HLR. This is mainly important for international mobile roaming. Outside North America the IMSI is converted to the Mobile Global Title (MGT) format, standard E.214, which is similar to but different from E.164 number (more or less a telephone number). E.214 provides a method to convert the IMSI into a number that can be used for routing to international SS7 switches. E.214 can be interpreted as implying that there are two separate stages of conversion; first determine the MCC and convert to E.164 country calling code then determine MNC and convert to national network code for the carrier's network. But this process is not used in practise and the GSM numbering authority has clearly stated that a one stage process is used [1].
In North America, the IMSI is directly converted to an E.212 number with no modification of its value. This can be routed directly on American SS7 networks.
After this conversion, SCCP is used to send the message to its final destination. For details, see Global Title Translation.
This example shows the actual practice which is not clearly as described in the standards.
Translation rule:
so we get 284011234567890 becomes 359881234567890 numbering plan E.214.
Translation rule:
so we get 310150123456789 becomes 14054123456789 numbering plan E.214.
The result is an E.214 compliant Global Title, (Numbering Plan Indicator is set to 7 in the SCCP message). This number can now be sent to Global Title Analysis. by onmobile