Just so that others can benefit from the information (not so easy to find out when you don’t know what to look for, easy to find when you know what you want), here’s how my system is configured to use a 3G mobile phone as a modem using TIM’s 3G network.
The interface configuration file (/etc/sysconfig/network/ifcfg-modem0) ended up as:
BOOTPROTO='none' DIALCOMMAND='ATDT' DIALPREFIX='' DIALPREFIXREGEX='' INIT1='ATZ' INIT2='' INIT3='AT+CGDCONT=,,"tim.br"' INIT8='ATM1' INIT9='' MODEM_DEVICE='/dev/ttyACM0' NAME='Nokia 6120 classic' PPPD_OPTIONS='' PROVIDER='provider0' SPEED='115200' STARTMODE='manual' UDI='' USERCONTROL='yes'
And the provider configuration file (/etc/sysconfig/network/providers/provider0) ended up as:
ASKPASSWORD='no' AUTODNS='no' AUTO_RECONNECT='yes' DEFAULTROUTE='yes' DEMAND='no' DSLSUPPORTED='no' IDLETIME='300' IPADDR='' ISDNSUPPORTED='no' MODEMSUPPORTED='yes' MODIFYDNS='yes' MODIFYIP='yes' PASSWORD='tim' PHONE='*99#' PROVIDER='TIM' REMOTE_IPADDR='' STUPIDMODE='no' USERNAME='tim' DNS1='126.96.36.199' DNS2='188.8.131.52'
The trickiest part was that we don’t get the DNS servers dinamically. The IPs above are from the OpenDNS project.
I hope it helps you to get started with whatever provider you have. 🙂