we use in our application for FTP up- and download always MDM.getDCD() == 1. This works fine in Europe and Afrika too.
Now we made test in USA and we never get DCD == 1. The normal transmission with HTTP (GET) works without any problems.
Has anyone an idea what could be the reason.
Any help is highly appreciated.
I’ve found the reason. The SIM card don’t allow to use port 21 on provider side. We change the SIM card and it works as expected.
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