[En-Nut-Discussion] Sony Ericsson MUX protocol

[Matej Kupljen]

Hi

> This would be useful.

Indeed :-)

> Most cellular modems have the ability to switch in and out of command
> mode (to issue AT commands) using the DTR signal.  If youre not using it
> for hanging up, you can initialise the modem prior to dialling to
> support this option.

Great. I'll check that.

> When you need to issue commands, you can pause PPP, lower DTR, issue
> your command, return DTR and then resume PPP.  To get PPP paused in
> earlier versions of NutOS, you use the ppp_hackup flag.  In latest
> version you need to make a mod which does the same thing.  Im expecting
> to implement this shortly by way of  issuing a _ioctl command (unless
> someone has already done it?)

Please let me know, how you have done (will do)  this.

There is another issue:
Suppose you have a PPP session active over the GPRS.
What happens if the SMS is received or somebody is dialing your modem?
If you use MUX, you get RING or +CNMI on "AT Channel". 
Does in this case you get notified by a DTR signal?

BR,
Matej