If you have subscribed to MTN Nigeria's 3G internet service and want to use it with your linux box then this might help you to get things working. Note that the following procedure is not restricted to MTN 3G alone. It can be used to connect to other networks' 3G or gprs service.
I am using ubuntu linux 8.10 (Intrepid Ibex) with the Huawei E170 usb modem supplied by MTN Nigeria.
If you are also using ubuntu 8.10 then things are a bit more easier. The following steps are what you need to do.
1- Right click on the network icon on the top panel and select "Edit Connections" this will bring up the network connections window
2- Select "Mobile Broadband" tab
3- Click on "Add". A wizard (druid in linux) will come up
4- Select Nigeria from the country list and you will get a list of mobile operators in Nigeria.
5- Select MTN , click "Next" and "Apply"
The next time you left-click on the network icon on the panel you will get a list of connections. Select the one you just created "MTN" and you will be connected.
Now you are ready to start surfing.
If you are not using Ubuntu 8.10 or you still can't browse after connecting then the following steps might help.
I am assuming you have a program called wvdial shipped with your distro. If it's not there then you will have to install it.
To check wether you have wvdial, open a terminal window and type wvdial . If you get any other message apart from "wvdial: command not found" then you have wvdial on your system.
Now you need to edit the wvdial configuration file located at /etc/wvdial.conf.
type sudo gedit /etc/wvdial.conf
this will open the configuration file in gnome's text editor with write previlege. If you are not using ubuntu/gnome open it with the appropriate method on your distro. But you need to open it with root privilege so that you can have read/write access to the file.
this is the configuration on my system
Phone = *99#
New PPPD = yes
Stupid Mode = on
Dial command = ATDT
Username = web
Password = web
Modem = /dev/ttyUSB0
Baud = 460800
Init2 = ATZ
Init3 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ISDN = 0
Modem Type = Analog Mode
put the following configuration and save the file. If you want to know more about the configurations then check the wvdial manpages or google for more info on wvdial.
Now in the terminal window type "sudo wvdial MTN"
A series of messages will pass over the console screen.
If you got a message "CONNECT" followed by some IP addresses then you are on.
Open your browser (firefox in my case), uncheck the "Work Offline" option under the file menu and browse away.