Hello.
I have RB411U and Sierra MC5728V. On Wiki this model doesn't listed but listed MC5727. This is same models as I understand. When I install MC5728V to miniPCIe in PPP doesn't appear PPPOut connection and System-Ports shows USB 2 Invalid.
If I use miniPCIe-to-USB adapter and use USB port, this modem appearing in PPP and System port.
Someone has any solutions?