GX450 AT&T LTE Setup Issues

I have a provisioned AT&T SIM card (I confirmed with AT&T that it has been activated) installed into my GX450. I’ve setup the APN within the web interface, both antenna are connected and at one point I had all, solid green lights (with no activity) but I was getting ‘could not connect to network’ though my cell phone could connect to the AT&T LTE network at the same location.

I then tried entering a SIM key ( I have no idea if this is needed ) and now I’m getting a message stating that my key is incorrect with 2 tries left. I’ve read the setup documentation, video on the Sierra website but I’m not sure if my issue is with the SIM card or ( most likely ) I’m missing a step in the web interface of the GX450.

Any hints, suggestions, links to docs, etc are greatly appreciated!


How you got the key? does your network provider has given that key or is it some predefined value?
If it’s provided by network provider, then you have to confirm with them.


Try the APN (Access Point Name) of “broadband”, configured in ACEmanager (WAN tab). If it connects on LTE then this is a account/provisioning issue on AT&T side