Configure 3G Modem on Fortigate

config system modem
    set status enable
end

diagnose sys modem wireless-id

you should get something like this:
vendor: 0x12d1, product: 0×1003, registered: yes

 set status enable
    set pin-init ''
    set network-init ''
    set lockdown-lac ''
    set mode standalone
    set dial-on-demand enable
    set idle-timer 5
    set redial none
    set holddown-timer 60
    set connect-timeout 90
    set wireless-port 0
    set phone1 "#777"
    set username1 "internet"
    set passwd1 ****
    set extra-init1 ''
    set peer-modem1 generic
    set ppp-echo-request1 enable
    set authtype1 pap chap mschap mschapv2

execute modem dial

If you are using the web interface of your FortiGate device, when you enable the modem interface you will get Modem option under System > Network section on the left side menu. You can set up some of the options, like phone or Extra Initialization String there too. Also you can condial or hang-up your 3g connection from there too.












































 
These are the pages I referenced when I was setting up my modem connection:

• http://anarosnetwork.blogspot.com/2010/08/fortinet-3g-redundacy.html
• http://support.maxtec.co.za/index.php?/Knowledgebase/Article/View/73
• http://www.scribd.com/doc/86341063/The-Fortigate-and-the-3G-Modem