Updating AT&T LTE Modem for 3G Deprecation¶
As AT&T continues to decommission 3G cell towers, Lantronix Local Managers with AT&T modems may fail to establish an out-of-band connection. The steps described in this article will correct / prevent a known issue with Cat3 and Cat4 LTE modems using AT&T cellular data that causes the LTE out-of-band connection to fail.
These updates are not required for CatM1 modems.
Symptoms¶
The symptoms that confirm the problem are failing out-of-band connections. We will see the ‘nxtgenphone’ APN in the first context of “AT+CGDCONT?” in show tech. It is fixed by manually setting the APN, as well as manually setting the CEMODE at or before LMS version 6.1.
LMS Versions 6.1 and below¶
Log into the Local Manager via the command line interface.
Access the modem resource using the modem command.
Access the modem terminal using the terminal command.
Run the following commands: * AT+CEMODE=2 * AT+CGDCONT=1,"IP","provider.apn.com"
Replace "provider.apn.com" with your assigned APN. A common default is "broadband" if you don't know your APN.
Exit the modem terminal using ~ [ENTER].
LMS Versions 6.2 and higher¶
Log into the Local Manager via the command line interface.
Access the modem resource using the modem command.
Access the modem terminal using the terminal command.
Run the following commands: * AT+CGDCONT=1,"IP","provider.apn.com"
Replace "provider.apn.com" with your assigned APN. A common default is "broadband" if you don't know your APN.
Exit the modem terminal using ~ [ENTER].
All Versions¶
Once the changes have been made, confirm the configuration by running pull tech and show tech. You should see the following entry (with your APN substituted).
You can then test your out-of-band connection using the outband cycle duration command. You can read more about the out-of-band LTE connection here: