My Device: Huawei, model: E1550, HSDPA USB Stick.

Step 1: Plug in device to your PC, open terminal console.

Step 2: Check CentOS auto detect device as GSM modem by command:


In the Result of dmesg command, you must see some following line:

GSM modem converter now attached to ttyUSB0

GSM modem converter detected

GSM modem converter now attached to ttyUSB1

usbcore: registered new driver option

Step 3: Install wvdial (w v d i a l ) – it’s require libwvstreams on dependency

#yum install wvdial

Step 4: Build configuration file for wvdial and save it to /etc/

#wvdialconf  /etc/wvdial.conf

Check the result message to make sure it success: “Found a modem on /dev/ttyUSB0 (or 1)” and “Modem configuration written to /etc/wvdial.conf”

Step 5: Edit wvdial.conf file:

#vi  /etc/wvdial.conf

Press I to edit this file, uncomment 3 line: Phone, Username, Password by remove “;” begin of lines.

Add a new line after Init command (Init1, Init2…). If you have 2 Init, you must add Init3 in new line (if you have init3 already, you must add Init4….)

Init3 = AT+CGDCONT=1,”IP”,”e-connect

P/s: e-connect is the APN name of your mobile provider, in this case, I use D-COM sim of Viettel so that I use: e-connect. Mobiphone is: m-wap. Vinaphone is: m3-world, username: mms, password: mms.

Edit account informations




Note: Phone must is *99# (all of country)

Username and password in this case is empty. You must add two symbol (single quote) after them.

Ok, Press “Esc” key to exit edit mode of vi, Press “:” key, enter “qw” and enter to save file.

Step 6: Connect to the internet with D-COM 3G


Please wait a minute, when you see some IP in your terminal, you are done.

Try open new terminal and ping google dns to make sure you can connect to the internet:



cuongk6t – Nguyen Quoc Cuong.