Re: UMTS usb stick MC998D (U998D): disconnect after 30-45 seconds

[Christian Jaeger <chrjae gmail com>]

> Looks like the modem does signal NO CARRIER at 20:57:11 around when you
> say the connection crashed.  One thing we could do is better handle the

That sounds like you think the modem was right in ending the
connection / thinking there is no signal. But this is weird for
several reasons:

- this always happens at around the same point in time after initial connect
- initial connect always works and data exchange works fast and well
till it blows up
- when it survives the magic point in time 20-35 seconds after initial
connect, the connection is stable, also, I can disconnect from nm and
reconnect and it will never blow up then.
- those 'crashes' ('blow ups', disconnects) happen independently of
how strong the signal is
- in my limited testing under Windows, the modem never crashed (I can
do more testing once I've reinstalled Windows somewhere)

So what I'm saying is that I've got no idea why the modem says "no
carrier", but it cannot be that there is no signal.

I suspect that either there's a bug in the modem that's only triggered
in some circumstances, or the "no carrier" answer is somewhat generic
and might mean something like "with the parameters that you requested
me to abide to, I cannot proceed", hence it might be an issue with the
configuration that nm sends to the modem.

Christian.