USB Modems In Backtrack

Configuring USB760 cell modem for Verizon Wireless:

Required Materials: Modern Laptop/Desktop Backtrack 4 Final USB Boot/DVD USB760 EvDO modem w/ Service This tutorial makes the following assumptions: Other then the USB stick, this tutorial assumes the modem will be the only device connected to your system during the execution of this tutorial. If you are planning on using other USB devices on the system, such as GPS, please connect and configure these devices after this tutorial is finished. Getting Started: Boot BT4 on your machine and log in as root after which start the windowing manager. This tutorial will use nedit to make the configuration files, however you are not limited to this and may use the editor of your choice. A few terminal windows will need to be open for this configuration.

Showing an open Terminal and text editor Nedit

Replicate the following data below and save it as “vzw_chat” to this location “/etc/ppp/peers/” on your system.

Saving the vzw_chat script

ABORT  'NO CARRIER' ABORT 'ERROR' ABORT 'NO DIALTONE' ABORT 'BUSY' ABORT  'NO ANSWER' '' ATZ OK-AR-OK ATDT#777 CONNECT \d\c

In nedit we need to make 2 configuration files for pppd, which is available within BT4. The configuration files are for Verizon modems, ATT configurations will need to edit their user line to match their ISP Replicate the following data below and save it as “vzw” to this location “/etc/ppp/peers/” on your system.

Saving vzw script

ttyUSB0 115200 debug defaultroute usepeerdns connect-delay  10000 user 8765309@vzw3g.com show-password lock lcp-echo-failure  4 lcp-echo-interval 65535 connect '/usr/sbin/chat -v -t3 -f  /etc/ppp/peers/vzw_chat'

Once the two files saved are saved to your system, its time to get the system to properly use the modem. If there is any troubles with the device not being located at ttyUSB0 you will need to edit the first line of “vzw” to match your devices location. If you have not already done so, please plug in your modem now. Allow 5-10 seconds for the system to settle down after the device is inserted. A caviot to this particular modem is that a SD Card is on this device which mounts to the system as /dev/sr0. We need to eject this device to get the EvDO device to function and identify properly. If you are using a different modem then the one specified your results will vary.

Shows the Dmesg output

root@bt:/# dmesg cut ... usb-storage:  device scan complete sr0: scsi3-mmc drive: 297x/297x sr 17:0:0:0:  Attached scsi CD-ROM sr0 sr 17:0:0:0: Attached scsi generic sg2 type  5 usb-storage: device scan complete sd 16:0:0:0: [sdb] Attached  SCSI removable disk sr0: CDROM (ioctl) error, command: cdb[0]=0x46 46  00 00 00 00 00 00 00 20 00 sr: Sense Key : 0x0 [current] sr:  ASC=0x0 ASCQ=0x0

If you issue lsusb command you will note this device as :

Showing lsusb output

root@bt:/# lsusb cut ... Bus 003  Device 002: ID 1410:5030 Novatel Wireless cut ...

Notice the vendor:product number of 1410:5030, this is the address of the SD Card on the device and will interfere with the configuration. The first command we will issue is to eject the SD card from the system:

root@bt:/#  eject /dev/sr0

Now the device has been ejected, wait approx: 5 seconds then issue lsmod again and compare the vendor:product number to the original

Showing lsusb output

 root@bt:/# lsusb cut  ... Bus 003 Device 002: ID 1410:6000 Novatel Wireless cut  ...

This identifier is now pointing to the EvDO modem. This allows the configuration to continue using a kernel module known as usbserial. This is done using modprobe usbserial and providing the vendor:product number we learned from the previous command as arguments.

Showing modprobe output

root@bt:/# modprobe usbserial vendor=0x1410 product=0x6000

If this command issued with out error you are almost on the Internet with your EvDO modem. The final step involves using pppd to connect. This connection is not persistent and if it drops, you will need to reconnect much like a vpn. Issue the following command to make the connection:

Showing pppd connected to the ISP

root@bt:/# pppd call vzw

Monitoring the connection can be accomplished with the following command:

 root@bt:/#  tail -f /var/log/messages Mar 12 15:38:01 bt chat[6462]: CONNECT Mar 12 15:38:01 bt chat[6462]:  -- got it Mar 12 15:38:01 bt  chat[6462]: send (\d) Mar 12 15:38:02 bt pppd[6461]: Serial  connection established. Mar 12 15:38:02 bt pppd[6461]: Using  interface ppp0 Mar 12 15:38:02 bt pppd[6461]: Connect: ppp0  <--> /dev/ttyUSB0 cut ...

Other things to take into consideration: If you remove the device you will need to reissue all the commands from “eject /dev/sr0″ to “pppd call vzw” If the connection drops after you have successfully connected 1 time, you just need to issue : “pppd call vzw” If you have other USB devices such as GPS, it will be located at “ttyUSB1″ after you enable the EvDO modem If you know bash or other languages, please do not hesitate to elaborate on these steps for automation