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Troubleshooting the USB Modem 453
USB Modem Support and Custom Options
As far as the driver can tell, the USB modem is functioning correctly. If there is no wireless
network connectivity, verify the APN, phone number and optional PIN#, user and password
settings. Each service provider’s network will have different requirements. See
Configuring
a USB Modem .
If this does not resolve the problem, use the Vendor id and product id to search the linux
community for any problems with this particular device. If the recommendation is to use a
device name override, use the “usb create modem-file devname ttyUSBn” (n = 1 to 4) to
create the override option. Please remember to save your changes and either reset the PCI
option line service or reboot the IOLAN, in order for the changes to take effect.
USB Modem Support and Custom Options
While we strive to include support for as wide a range of USB modems as possible, our support for
USB modems is currently limited to the Communication Device Class Abstract Control Model
interface (dev/ttyACMx device node), and the USB Serial Converter support for generic GSM and
CDMA modems interface (dev/ttyUSBx device node). The IOLAN attempts to initialize the USB
modem assuming the CDC-ACM type device, and after 30 seconds and multiple retries, it will try to
initialize using the USB serial converter generic GSM/CDMA method. This latter method, requires a
USB communication utility called “usb_modeswitch” that has a database of USB modems of this
class. Should you have a USB modem that is not in our database, but is available by way of the
linux internet community, please follow instruction below on how to download the file to the IOLAN.
or contact Perle support for assistance.
There are also USB modems that require that a different device node be used other than the default
/dev/ttyUSB0 device nodes. If after validating your USB modem configuration, you still do not have
wireless connectivity, you may need to search through the Linux community using your USB
modem’s vendor id and product id, to determine if an override for the device node is required. The
“usb modem status” command will output the information you need to do the search for connectivity
issues in the linux community. To override the default device name, please use the following
command:
usb create modem-file devname ttyUSBn (where n is an interface number between 1 - 4)
Should you find it necessary to remove the devname override, please use the “usb delete modem-file”
command. This command will also remove any custom, downloaded usb_modem and modeswitch
files (see next section).
Downloading Custom USB Modem Configuration Files
If you have a usb_modeswitch file which you have found for your USB modem and this modem is
not currently in the IOLAN database, you can download the file as follows;
1) Connect a terminal to the IOLAN using the console port and cable.
2) Login as admin
3) Issue the following CLI command;
netload customapp-file <ip_address> <filename>
ip_address is the address of your tftp server
filename is the usb_modeswitch file full path and name
This will transfer the usb_modeswitch file from your TFTP server to the IOLAN. The file name is in
the format “vvvv:pppp” where;