I tried establish a PPP connection over LTE using ATD command but the IPCP protocol failed.
I defined APN key with AT+CGDCONT command.
I think I forget something.
Please provide the following result and PPP logs?
Could you first to check with PPP dial up connection in windows?
or do you test in Linux?
Sorry, I solved my problem.
It was a parameter in bad endianness format ( length = 0x0a00 instead of 0x000a ).