I am manually connecting to WWAN via a Sierra EM7345 modem. The NetworkManager doens't seem to start ModemManager. Only if the latter is ran manually, it then appeas in NM. It is the same problem discussed at http://forums-web2.gentoo.org/viewtopic-t-994224.html?sid=643d116182decb2cf23a9d0d6a43ca9a.
Is there a way to fix this? Add MM as a service (openrc)?