Huawei E173s

This page describes how to set up Huawei E173s 3G USB modem on Arch Linux. It involves switching the USB stick from CD-ROM mode to modem mode using usb_modeswitch, loading the appropriate kernel driver for the modem and, finally, making a connection to the network with sakis3g.

Check modem

Install usbutils (base) if not installed:

pacman -S usbutils

Plug in the modem and run lsusb:

lsusb | grep Huawei

The output should be something like this:

Bus 003 Device 003: ID 12d1:1c0b Huawei Technologies Co., Ltd.

The ID 12d1:1c0b refers to vendor id and product id. If you get different values, it means your modem is not Huawei E173s (of course, you can always open the USB stick to double check).

Set up usb_modeswitch

Install usb_modeswitch (community) if not installed:

pacman -S usb_modeswitch

Create a configuration file for your modem:

nano /etc/usb_modeswitch.d/12d1:1c0b

Add the following lines:

DefaultVendor=0x12d1 
DefaultProduct=0x1c0b 
TargetVendor=0x12d1 
TargetProduct=0x1c05 
CheckSuccess=20 
MessageEndpoint=0x0f 
MessageContent="55534243123456780000000000000011062000000100000000000000000000"

At this point if you remove your modem and re-insert it it should switch to modem mode automatically or just use the following line to do it manually:

usb_modeswitch -c /etc/usb_modeswitch.d/12d1:1c0b

Check if the modem is switched

lsusb | grep Huawei

The output should be something like this:

Bus 003 Device 003: ID 12d1:1c05 Huawei Technologies Co., Ltd.

Note that the product ID has changed from 1c0b to 1c05. It means that the USB stick can now be used as a modem. Also note that it can take some time (probably not more than 15 seconds) for the modem to switch if you removed and re-inserted it instead of running usb_modeswitch manually.

Connecting

The easiest way to connect is with sakis3g. Install ppp (base) and net-tools (core) if not installed:

pacman -S ppp net-tools

Download and install sakis3g from http://www.sakis3g.org/ (it's also available from AUR):

wget http://www.sakis3g.org/versions/latest/i386/sakis3g.gz
gunzip sakis3g.gz
mv sakis3g /usr/bin

Run sakis3g:

sakis3g --interactive

You will have to provide your APN, username and password, assuming everything goes right you should be connected by now.

Connect at system startup

First you need to create a configuration file:

nano /etc/sakis3g.conf

Add the following lines (CUSTOM_APN, APN_USER and APN_PASS refer to your APN, username and password respectively, you may have to adjust them):

OTHER="USBMODEM"
USBMODEM=12d1:1c05
USBDRIVER="option"
APN="CUSTOM_APN"
CUSTOM_APN="general.t-mobile.uk"
APN_USER="t-mobile"
APN_PASS="tm"

What you need to do is to run sakis3g connect at system startup. The easiest way to do this is to add these lines to /etc/rc.local:

sakis3g connect --console
sleep 3

The second line gives you time to examine the output of sakis3g at system startup to see if everything is working as it should, if it is, you can just remove it later. Another option, if you are using X but not using a login manager like GDM, is to put it in your .xinitrc (see the first line):

sudo sakis3g connect &
exec openbox

For this to work you need to the following line to /etc/sudoers:

<username> ALL=(ALL) NOPASSWD:/usr/bin/sakis3g

Replace <username> with your username.

External links

• http://wiki.sakis3g.org/wiki/index.php?title=Mode_switch