ppp connection using gprs modem

I am trying to connect to a GPRS modem using PPP via a serial port.
I can get the modem to respond to AT commands. But when I run the ppp daemon on the serial port of the modem, the connection is not established.
/sbin/ifconfig shows an entry for ppp0 but no ip address is displayed.

initial commands:
stty baud=115200 </dev/ser1 +ihflow +ohflow
slay io-net
/sbin/io-net -p pppmgr -p tcpip
qtalk // to input at commands to the modem

at commands:
at10001 // puts the modem in ppp mode

/usr/sbin/pppd /dev/ser1

These are my /etc/ppp/option settings:

/sbin/ifconfig displays:
lo0: …
ppp0: flags=8050<POINTOPOINT,RUNNING,MULTICAST> mtu 1500
nwid “”
tunnel inet ---->
media: autoselect

am I forgetting something important?

You might want to take a look at those ppp scripts and see if you missed something: