Sierra Wireless AirCard 313U (AT&T Momentum 4G) on Ubuntu Linux

Question

I'm trying to get a Sierra Wireless AirCard 313U (more specifically, the AT&T Momentum 4G) working under Ubuntu Linux.

I've looked at a number of pages so far:

How to connect internet using AT&T USBConnect Momentum 4G (AC313U) on Ubuntu/Mint?

Can I use a Sierra Wireless Modem on Linux Machines (direct IP modems)?

Setting up a Bigpond NextG wireless connection on Linux

My understanding based on the above is that the Sierra Wireless drivers are already included with non-ancient Linux kernels, and the device should be automatically detected, with some /dev/ttyUSB* device files being created as a result. I don't see these files, however.

dmesg shows a couple lines like

[ 555.877426] usb 2-2: config 1 has an invalid interface number: 7 but max is 5

which appears to suggest that the device is in its software installation mode, rather than modem mode. I'm not sure how to get the device into modem mode; my understanding is the driver is supposed to be doing this anyway.

I've tried plugging in under Ubuntu 12.04 and 10.04.04, with basically the same results (i.e., device not detected). I was able to modprobe sierra and modprobe sierra_net (on 12.04 at least; 10.04.04 didn't seem to have the sierra_net module), so the drivers should be included.

The device did work on a couple Windows 7 machines I tried it on, though a funny thing is that it didn't automatically install its drivers like it was supposed to; I had to go download them from AT&T's website and install them myself.

Answer 1

I had an AT&T mobile 3G USB plug-in at my business back before cable-modem internet was available. It was my stand-by for when the DSL went out.

I discovered the easiest way to make it work was to have it plugged into the computer when installing Ubuntu. This was what we did to get internet when going on the road and needing to run peoples' credit cards from our POS app in ubuntu. I recall the Ubuntus we were using on the road were 10.04...?

When it was at work, these were the magic steps used to make it come online... ssh into the firewall ubuntu server (edited: just checked and the firewall is 9.04):

root@wall:~# cat do_this_for_3g.txt 
nohup pppd call gsm &

# Then after DSL works, to kill the 3G...
ps aux | grep pppd
# root     18716  0.0  0.0   7528   888 pts/0    R+   12:08   0:00 grep pppd
# root     23021  0.0  0.1  21668  1316 pts/0    S    Mar15   0:00 pppd call gsm

kill 23021

/etc/init.d/networking restart

Notice that gsm_chat is a script in /etc/ppp/peers:

root@wall:/etc/ppp/peers# cat gsm_chat 
# Connection script for Sierra Wireless GSM/UMTS modems
# Note: This demo script is setup to work on the Cingular EDGE network
#
SAY 'Starting Sierra Wireless GSM connect script...\n'
SAY '\n'

#######################################
SAY 'Setting the abort string\n'
SAY '\n'
# Abort String ------------------------------
ABORT 'NO DIAL TONE' ABORT 'NO ANSWER' ABORT 'NO CARRIER' ABORT DELAYED

#######################################
SAY 'Initializing modem\n'
# Modem Initialization 
'' AT
OK ATZ

#######################################
SAY '\n'
SAY     'Setting APN\n'
# Access Point Name (APN) 
# Incorrect APN or CGDCONT can often cause errors in connection.
# Below are a bunch of different popular APNs

#REG:\s1 AT+cgdcont=1,"IP","proxy"
#OK     'AT+CGDCONT=0,"IP","proxy"'
#OK     'AT+CGDCONT=1,"IP","proxy"'
#OK     'AT+CGDCONT=2,"IP","proxy"'
#OK     'AT+CGDCONT=0,"IP","ISP.CINGULAR"'
OK     'AT+CGDCONT=1,"IP","ISP.CINGULAR"'
#OK     'AT+CGDCONT=2,"IP","ISP.CINGULAR"'

#######################################
SAY '\n'
SAY     'Dialing...\n'
# Dial the ISP, this is the common Cingular dial string

OK ATD*99#
CONNECT ''