Digital Matter Cellular devices have an Auto-APN feature that can make the SIM card experience "plug and play".
Auto APN is activated when the Admin Parameters are blank. This is the default state for the devices.
It is recommended that once your have your device online you fix the APN to the correct setting in the Admin Parameters (Multi-APN feature). Auto-APN should be thought of as a tool to get your device online easily.
How Auto-APN works:
Auto-APN allows the device to analyse the SIM card and select the correct APN details from a list that is pre-loaded in the device’s firmware. This means that the device can be shipped world-wide without requiring specialist APN setup for SIMs.
The device queries the Mobile Country Code (MCC) and Mobile Network Code (MNC) from the SIM, using the IMSI. It tries to find matching MCC and MNC entries in an APN table in the firmware.
The table provides an APN Name, Username and Password for the MCC/MNC combination. Username and Password may be blank.
The table contains some APN's that are specific to clients, so it is not made public. Please contact support to find out if your local APN is on the list.
There are multiple scenarios when looking up an MCC MNC combination:
- No matching entry: if the MCC and MNC do not appear in the table, the device will use the “internet” APN with no username and password.
- Single matching entry: there is 1 MCC and MNC entry that matches. The device will use the APN details in the table.
- Multiple matching entries: there are multiple matches for the MCC and MNC. The device will try the first entry. If it works, it will continue to use those details. If it doesn’t work, it will move to the next matching entry. If it continues to fail it will keep rotating through the matching entries.
Note that the IMSI is fixed on the SIM. If the SIM roams onto another network, the IMSI does not change and the Auto-APN details will be for that of the home network. For roaming, see the section on Multi-APN.
- IMSI indicates MCC=655 (South Africa) and MNC=01 (Vodacom). If there is no matching entry for this in the Auto APN table, “internet” will be used.
- IMSI indicates MCC=424 (UAE) and MNC=03 (Du). The may be a single matching entry for this in the Auto APN table. The table indicates "du,," should be used. The ",," commas indicate no username and password.
- IMSI indicates MCC=505 (Australia) and MNC=01 (Telstra). There may be 2 matching entries. The first is "telstra.internet,," and the second is "telstra.m2m,,". In this case the device will try each APN until one of them works. Upon success it will try to keep using that APN until there are repeated errors, when it will try the next entry in the table.