using a GPRS moden to go online and send SMS (but I fail)

[robert rottermann]

Hi there,

I want to use a gprs modem to go online (I am using adafruit fona)
Setting up a connection using pppd works fine (and is rather fast).
I also want to send and receive sms.
This works also fine by sending AT commands to the respective device.

Unfortunately  I can do only either or.
But I would like to do both at the same time.

Now I read that the modem has to be set into multiplex mode with
AT+CMUX=...
so more than one command can be executed at the same time.

Unfortunately I find no documentation on how to do that.
I do not even know what parameter to pass to that command.

does anybody of you have an Idea or can give me a pointer to some documentation.

thanks
robert