This little script helps me to establish reliably a UMTS connection on my ThinkPad T420s which contains a Ericsson F3507g Mobile Broadband Module. If that hardware fails to get a WWAN connection, the modem often needs a complete reset and reinitialization. Also, the network device needs some reset during that phase. This script takes care of that hassle. It retries as often as necessary until the UMTS connection is really established.

The wwan-helper is meant to run as hook script for the ifup / ifdown mechanism, but should also work on other networking systems.

If that script is also helpful for you, some small donation would be nice:

Have fun!

Getting Started

Make sure that the chat system utility is installed on your system:

/usr/sbin/chat -h

If it isn't, the following command will install it on Debian:

aptitude install ppp

Download wwan-helper:

git clone https://github.com/vog/wwan-helper.git /etc/wwan-helper

Configure your APN and PIN in /etc/wwan-helper/config:


Protect your configuration file:

chmod 600 /etc/wwan-helper/config

Enable wwan-helper:

ln -s ../../wwan-helper/wwan-helper /etc/network/if-pre-up.d/wwan-helper
ln -s ../../wwan-helper/wwan-helper /etc/network/if-post-down.d/wwan-helper

Note that this doesn't require any special settings in your /etc/network/interfaces. The following standard entry is all you need:

iface wwan0 inet dhcp

If you have a Linux kernel 3.2 or older, use usb0 instead of wwan0.

Disabling wwan-helper

If you have any trouble, you can disable wwan-helper simply via:

rm /etc/network/*/wwan-helper

Further Information

For debugging, you can execute the pre-up and post-down phases directly via:

IFACE=wwan0 PHASE=pre-up /etc/wwan-helper/wwan-helper
IFACE=wwan0 PHASE=post-down /etc/wwan-helper/wwan-helper

For background information, please have a look at:

Fork me on GitHub