How do I establish a mobile broadband connection from the command line?

Question

I run Ubuntu 12.04 on an old iMac G3. Since the GUI is too resource heavy I have disabled the display manager (lightdm) and am currently running the computer in console mode. How do I establish a mobile broadband connection from the command line?

When I connect the modem it shows up as ttyUSB0 in the Network Manager device list:

$ nmcli dev
DEVICE     TYPE              STATE        
ttyUSB0    gsm               disconnected    
eth0       802-3-ethernet    unavailable

I have also copied a working connection configuration file from another computer to /etc/NetworkManager/system-connections/Com\ Hem\ Default\ 1. Still, when I try to connect I get an "unknown connection" error:

$ nmcli con up id "Com Hem Default 1"
Error: Unknown connection: Com Hem Default 1.

Any clues?

Answer 1

wvdial is the tool you need. Install it with sudo apt-get install wvdial if needed. You can configure the connection by editing /etc/wvdial.conf:

[Dialer Defaults]
Phone = <dial-out number here>
Username = 
Password = 
New PPPD = yes

Their man-pages will be really helpful I think. man wvdial and man wvdial.conf for details.

Answer 2

The CLI way

There are 3 files involved “/etc/ppp/peers/provider”, “/etc/chatscripts/pap” and “/etc/ppp/chap-secrets”.

#/etc/ppp/peers/provider

user "user"

connect "/usr/sbin/chat -v -f /etc/chatscripts/pap -T *99#"

# Serial device to which the modem is connected.

/dev/ttyUSB0

# Try to get the name server addresses from the ISP.

usepeerdns

# Use this connection as the default route.

defaultroute

replacedefaultroute

# Makes pppd "dial again" when the connection is lost.

persist

# no compression - ppp is used only until the modem

novj

novjccomp

nopcomp

nodeflate

noccp

#debug

“/etc/chatscripts/pap”:- ABORT BUSY

ABORT           VOICE

ABORT           "NO CARRIER"

ABORT           "NO DIALTONE"

ABORT           "NO DIAL TONE"

""              ATZ

OK ATE0V1&D2&C1S0=0+IFC=2,2

OK AT+CGDCONT=1,"IP","3internet"

OK ATDT*99#

CONNECT         ""

“/etc/ppp/chap-secrets”:- # Secrets for authentication using CHAP

# client        server  secret                  IP addresses

3ireland        *       3ireland

The most important setting is for the APN in the chat script “3internet”, change this to suit your own provider. You may also need to change usernames and passwords. Until you are confident the connection is working correctly you may also want to enable debugging by uncommenting “#debug” in /etc/ppp/peers/provider. Commonly with 3 the DNS servers don’t get doled out correctly so it may be wise to comment “usepeerdns” and put the DNS servers for your connection into “/etc/resolv.conf” manually.

To start the connection simply type “pon”, to stop conversely “poff”. To start the connection on boot add “pon” to “/etc/rc.local”. To share the connection enable ip forwarding in “/etc/sysctl.conf” and have iptables configured correctly. See http://www.johnlewis.ie/the-importance-of-a-minimal-firewall/ for more information on the firewall side.

[refer] http://johnlewis.ie/mobile-broadband-from-the-command-line-in-ubuntu/