Technical Note : FortiOS enhanced Modem command in 4.0 MR1 release to set the "ttyusb" port

[dchan]

Description

Each USB wireless modem has a specific dial-out ttyusb port,  usually the Vendor of the modem has this information. You can use the following FortiGate CLI commands to test the validity of the USB ports.

• Under normal conditions you should see the following output:

FGT#diagnose sys modem com /dev/ttyusb1

Serial port: /dev/ttyusb1

Press Ctrl+W to exit.

• The ports that do not respond will give this output:

FGT#diagnose sys modem com /dev/ttyusb0

Can not open modem device '/dev/ttyusb0': Broken pipe

Until FortiOS 4.0, each firmware version uses a specific USB port to dial out which cannot be changed. Since FortiOS 4.0MR1 you can select the USB dial-out port by CLI.

The new configuration command is :

config system modem
    set wireless-port <tty>
end

Where <tty> is the value of the port :

1 = ttyusb0

2 = ttyusb1

3 = ttyusb2

In conclusion, if you are running into this USB port mismatch issue, you can get information from your modem Vender about the USB port being used by the modem and then use the FortiOS modem command to match the port config.

Scope
FortiOS 4.0MR1 and above.