UMTSkeeper: keep your UMTS/GPRS/GSM connection alive automatically

by Mintaka

This page is about UMTSkeeper version 2 (Python version). If you need information about version 1.xx (BASH version), find it here.

Perhaps you know one of the following scenarios:

You want to share a single internet connection with several people in your home. For this you set up a small gateway machine running Linux. You live in a somewhat remote location where cable is not available and the only affordable connection is via UMTS or GPRS cell phone modem. The quality of the connection is sometimes poor so that you suffer from frequent drop-outs. There's no other way than manually re-connecting every so often.

Your 3G mobile internet contract perhaps has a monthly transfer limit. In case you get above you are charged phantastic amounts. There's no easy way to monitor your transfers in real-time and disconnect before the limit is reached.

Monitoring the internet connection with some daily/monthly transfer statistics would be nice so that you can investigate the download behavior of net applications and your general usage.

Good news, now there is a way. UMTSkeeper does just that, it will connect the modem automatically and re-connects whenever possible. It can also do basic IPtables setup for NAT (forwarding a single internet connection to the internal network). Online transfer statistics as a bonus.

Please be aware that version 2 is currently in beta state. This means that there will be a lot of changes during the coming weeks, as I fix errors and add new features. The versions I put online run stable on my machine. However, this is a complete re-write of the program with lots of new functionality, and therefore you might encounter oddities. I'm happy about any feedback. If you encounter a flaw, please let me know (best attach the logfile /var/log/umtskeeper.log, the error.log, and your command line or config file if you have one). If you really need it more widely tested, resort to version 1 (which has its shortcomings but works well enough).

umtskeeper screenshot
Screenshot of the UMTSkeeper statistics page (version 2.00).
Click image to enlarge.



To run the program, Python2 needs to be installed (it's made with 2.7). Python is installed with many distributions by default. If not, it should be in your package repositories, or you can download it from here: Be aware that Python3 is not necessarily backward compatible with Python2 code. It's likely that UMTSkeeper will not run with Python3 - I did not test it yet.

UMTSkeeper uses the Sakis3G script by Sakis Dimopoulos to set up the modem and connect to the net. You can download Sakis3G from the Sakis3G website (the author of UMTSkeeper is not afiliated with Sakis Dimopoulos). I take the "binary free" version, yet the "full" (including usb_modeswitch) will do as well. Read the manual!
If Sakis' website is down then you can get it from the Internet Archive Wayback Machine:*/ There is a (binary free) version available on, too: (thanks BigCowPi for the link).

Upgrading from version 1.xx

Version 2 is designed to be a drop-in replacement for version 1.xx. Anyway, make a backup of your files first, then extract the new program files into the version 1.xx program directory. Version 2.xx will first convert your umtskeeper.stat file to a new format and add a few items. The px*.png files are not needed anymore.


I'll do the commands that have to be given as the root user (or superuser, the general linux system administrator), using the sudo program, which asks you for your own password every time and which is the standard way on freshly installed Ubuntu systems. On other systems you may type su to become root. (sidenote: to activate the root account on Ubuntu, define a password for it: sudo passwd)
Also, for packet installation, I will use the apt-get command, which is standard on Debian based distributions (also various flavors of *ubuntu and Raspbian). On other distributions I assume that you are familiar with whatever packet installer it uses (yum etc.).

Before you proceed, make sure you have read and understood the license agreement. For your convenience, I made an excerpt. It's not an endless read of tyring legal stuff.

UMTSkeeper and Sakis3G should reside in the same directory. In this example it's /home/mintaka/umtskeeper/ - a subdirectory of my home directory, where mintaka is my user name. Substitute mintaka with your own user name. (Alternatively, you can put it in any location you find suitable). Typing pwd will show you the exact location you are working in which you will need later when you automate things (thanks BigCowPi for simplyfying this procedure).

If you don't yet have internet on your target system, download and transport the files there. The archive contains a "readme" file with these instructions as well.

In a terminal, download and extract both scripts and make them executable (input line-by-line):

cd ~
mkdir umtskeeper
cd umtskeeper/
wget ""
gunzip sakis3g.gz
chmod +x sakis3g
wget ""
tar -xzvf umtskeeper.tar.gz
chmod +x umtskeeper

Ubuntu users: do not set up an automatic connect with the GNOME network manager because it interferes with Sakis3G. You will likely use a headless machine, therefore the NM will not be useful anyway, so consider to uninstall it. This might apply to other distributions as well, I didn't test. You can still set up your network connections in /etc/network/interfaces. To remove, type sudo apt-get remove network-manager.

Also make sure that your system properly detects the modem. The usual type of modem available will first register as a storage device to the system, containing a Windows executable which installs the modem manager software (on Windows, that is). On Linux, these devices may need to be switched to modem mode with the program usb_modeswitch, which should be available in your packet repositories (try sudo apt-get install usb-modeswitch before you go compile it yourself). There's also a "binary" version available on the Sakis3G website which includes usb_modeswitch. Many modems are pre-configured in usb_modeswitch to work out-of-the-box, so there's no more to be done there. If your modem is not switched automatically then you can find more on configuring usb_modeswitch on the usb_modeswitch site and its forum.

The clever way is to first connect manually with Sakis3G in interactive mode. Sakis3G will give you hints for the options to use. Do it as root:

sudo ./sakis3g --interactive

Hint: if you are asked for APN user or APN password but you have none, enter "0".

First Run

If your connection works in interactive mode, unplug and re-plug your modem and try with UMTSkeeper with all the switches and options, also as root.
For example (this is a single line, mind the quotes!):

sudo ./umtskeeper --sakisoperators "USBINTERFACE='0' OTHER='USBMODEM' USBMODEM='12d1:140c' SIM_PIN='1234' APN='CUSTOM_APN' CUSTOM_APN='' APN_USER='0' APN_PASS='0'" --sakisswitches "--sudo --console" --devicename 'Huawei' --log --nat 'no'

UMTSkeeper will stay running after this. To end it, press the key combination CTRL+C.

Sidenote: You can watch the log flow by typing tail -f /var/log/umtskeeper.log if you like. End the watch with the key combination CTRL+C.

When run for the first time some log files will be created, among them /var/log/umtskeeper.log (option --log, the main log file), umtskeeper.stat.html (HTML statistics file to view in your web browser), and umtskeeper.stat (the file which keeps the numbers for the next run). Without the option --silent, the log is also printed on screen. It should contain something like this:

1cat /var/log/umtskeeper.log
22013-07-23 12:16:05 Start: PID = 21338
3Main stats file not found.
This is normal for the first run when the main statistics file umtskeeper.stat is not yet present. Such an output should only make you worry if they happen with subsequent starts. Sometimes, UMTSkeeper is interrupted just when it is in the middle of writing the stats file, which would be fatal. For such (rare) cases, a backup of that file is kept.
4Main stats file is incomplete. This happens in rare cases when UMTSkeeper is killed in the wrong moment. Trying to load backup file. This can cause slight inacurracies in the statistics.
5Main stats file backup not found. Possibly this program is being run for the very first time.
62013-07-23 12:16:05 stats interval = 8s, connection check interval = 32s
7Monthly stats file not found, setting up a new one.
New statistics files have been created. These are comma-separated-values files which you can import into your favorite spreadsheet software to plot lenghty graphs etc. - these statistics are kept until you manually delete them. The files are: umtskeeper.hourly.csv, umtskeeper.daily.csv, umtskeeper.monthly.csv.
8Daily stats file not found, setting up a new one.
9Hourly stats file not found, setting up a new one.
10Internet status:
11Cell network: No modem plugged.
This is OK if you have the usual type of modem that first registers as a storage device to the system. The script will wait until the device is switched to modem mode.
122013-07-23 12:16:41 Internet connection is DOWN. Calling Sakis3G connect...
13Sakis3G cmdLine: nice ./sakis3g connect --sudo --console USBINTERFACE='0' OTHER='USBMODEM' USBMODEM='12d1:140c' SIM_PIN='1234' APN='CUSTOM_APN' CUSTOM_APN='' APN_USER='0' APN_PASS='0'
Commands that are being sent to Sakis3G. Use this for trying manually if something doesn't work. Sakis3G is called under the command nice which means that the program will run with lower priority. S3G is CPU hungry so you want it to play nicely and not interrupt other running processes.
14Sakis3G says...
15E1550 connected to PROVIDER (13579).
The connection has been established.
162013-07-23 12:17:14 Testing connection...
172013-07-23 12:17:24 Success... we are online!

If you unplug your modem now and re-plug it again then the connection should be established automatically. Give usb_modeswitch and Sakis3G a little patience.

Automatic Start

Last, you want to start UMTSkeeper automatically after boot. Put a line into /etc/rc.local like this (it's a single line which will make it run in the background and redirect screen output to an error.log file): /etc/rc.local has to be edited by the root user. Replace the path /home/mintaka/ in this example by the path you found out previously.

/home/mintaka/umtskeeper/umtskeeper --sakisoperators "USBINTERFACE='0' OTHER='USBMODEM' USBMODEM='12d1:140c' SIM_PIN='1234' APN='CUSTOM_APN' CUSTOM_APN='' APN_USER='0' APN_PASS='0'" --sakisswitches "--sudo --console" --devicename 'Huawei' --log --silent --monthstart 8 --nat 'no' --httpserver &>> /home/mintaka/umtskeeper/error.log &

A line for only logging transfer statistics on wlan0 would for example look like this:

/home/mintaka/umtskeeper/umtskeeper --logonly --log --silent --monthstart 14 --iface 'wlan0' --httpserver &>> /home/mintaka/umtskeeper/error.log &


Currently, UMTSkeeper does not have an uninstaller (just as there is no installer). To remove it without a trace, delete /var/log/umtskeeper.log and the whole program directory, and any special HTML dirs and temp dirs you may have made. That should be all.

Parameters and Customization

Configuration file:

All configuration can can be done with command line parameters or in a configuration file. UMTSkeeper will look for <progPath>/umtskeeper.conf (1). The configuration goes this way: (1) overrides the program defaults, and values in a config file given by the --conf <conffile> command line directive overrides (1). Further, any parameters given on the command line will override the values from the config files. An example config file (umtskeeper.conf.sample) with a lot of explanation is included in the package.


Retry connecting for example if connecting was suspended by --sakismaxfails.
Manually reset the monthly transfer counter.
Reset the transfer amount counters. This will not reset the rate counters. Data will be deleted without asking again.
Reset the rate counters. This will not reset the transfer amount counters. Data will be deleted without asking again.
stop, quit, end
Any of these will terminate a running UMTSkeeper.


Log to file (default: don't log). See also: logfile.
Do not connect to internet. Use this for only logging statistics on a connection. Recommended only for (W)LAN devices (default: do connect).
Force running without requiring root privileges. The default behaviour is that if writing to system dirs returns "permission denied", it switches to no-root mode. This means, that all temp files and logs will be stored in the program directory. This switch is the equivalent of setting the config variables conf['logFile']=progPath+'umtskeeper.log', conf['tempPath']=progPath, and conf['statFilePath']=progPath.
Don't write statistics files (default: write them).
Generate a HTML page without the internal webserver running. The HTML file is by default written to the temp dirctory: /run/umtskeeper/umtskeeper.stat.html or /var/run/umtskeeper/umtskeeper.stat.html. If --htmlPath is given then the HTML file is copied there. (default: none)
Suppress screen output (default: verbose).
Run the internal webserver (default: off). See also --httpport.


--conf </path/to/configfile>
Specify a configuration file to use. For the order of configuration, look above. (default: none)
--iface <iface>
Network interface to monitor (default: ppp0).
--nat <iface>
Enable internet connection forwarding (NAT). <iface> is the name of the network adapter that connects to the internet. Often, this is ppp0 (look it up with ifconfig when the connection is up). Set to 'no' if no forwarding is required (default: no).
--testcycle <s> (formerly --interval)
Test connection in intervals of s statistics cycles (1 cycle is about 4 seconds) (default: 8).
--sakismaxfails <n>
Maximum of failed connection retries by Sakis3G in sequence until the program gives up (actually it tries twice in a cycle). This parameter should help to save on power, especially with battery driven machines. Sakis3G is CPU intensive. So, if for any reason (modem unplugged or other failure) the connection doesn't work then we'd better give up constantly trying. See also --sakisfaillockduration. (default: 4)
--sakisfaillockduration <s>
Duration (in seconds) after which we retry to connect after the maximum of failed connection retries was reached. See also --sakismaxfails. (default: 300)
--logfile "<file>"
To specify an alternative log file (default: /var/log/umtskeeper.log). This implies the option 'log'.
--devicename "<string>"
Set device name (eventually needed for device reset, this should be a unique identifier containing only letters and numbers. Get it with lsusb (don't listen to what Sakis3G says).
Example: lsusb may return the device name string: ZTE WCDMA Technologies MSM MF110/MF627/MF636. Any unique part of this name is ok to take as the device name. So, --devicename "MF636" would be appropriate here.
--statfilepath "<path>" (formerly --statpath")
Write statistics files to this location. (default: script path)
--temppath "<path>"
Specify alternative path for temporary files. The default is to make a subdirectory in /run/ or /var/run/ (whichever is found), which is a tmpFS (ramdisk) filesystem on most platforms, and therefore the contents are lost on shutdown.
--htmlpath "<path>"
Webserver path to copy the stats HTML file to (default: empty - do not copy)
--httpport <port>
Port on which the internal webserver is listening. Setting the port implies --httpserver (default: 8000)
--limitday <limit>
Set daily transfer limit (in bytes)
--limitmonth <limit>
Set monthly transfer limit (in bytes)
--monthstart <day>
Day of month when monthly count begins. This is typically the day on which your monthly contract starts.
--sakisswitches "<switches>"
Set switches to pass to Sakis3g.
--sakisoperators "<operators>"
Set operators to pass to Sakis3g.


Please read the license agreement before you use this program. It won't hurt - for your convenience, I made an excerpt.

Download UMTSkeeper
Sakis3G website (alternatively from the Wayback Machine)


Further Reading and Acknowledgements

BigCowPi (Andy Thomson) has a great tutorial on turning the Raspberry Pi into a cell network internet gateway and wireless router, using UMTSkeeper/Sakis3G. This should also work with other computers. Also, there is a tutorial about setting up a NAS (network storage) using the RasPi which can be combined with the gateway/router function, and a good collection of other RasPi related stuff. Check out his site.

Many thanks to for Free DNS hosting.


Sakis3G (alternatively from the Wayback Machine)

Questions and Answers

Q: Do I really *have* to run the thing as root?

A: No. For some functions of Sakis3G, root access is necessary. Try if Sakis works without sudo, and if it does there's nothing wrong with running UMTSkeeper as an ordinary user. In this case, all logfiles will be created in the program directory.
Deamonising it with rc.local will run it as root, though.

Q: Does the webserver function put my system at a risk?

A: It shouldn't. The HTTP server that UMTSkeeper uses is a very rudimentary implementation that uses the BaseHTTPServer module of Python. It's specially tailored so that it serves only those files that are on its whitelist, and everything else will receive a 403 (forbidden) reply. It does not run any scripts besides those in UMTSkeeper. The current implementation will not even parse the URI arguments. Access restriction by IP range is possible.

License and Disclaimer

This program is released under a double license

Primarily, the Hacktivismo Enhanced-Source Software License Agreement (HESSLA), which can be found in full and with an additional statement about its objectives, at;
and for compatibility reasons, the GNU General Public License (GPL), see

While the GPL contains the terms and conditions under which the software and derivative works thereof can be freely distributed, and thus is aimed primarily at software developers, the HESSLA, while granting the same rights and obligations to modify and distribute the software, contains additional terms that govern the use of the software. This makes the HESSLA function as a contract between the author and the user, rather than just being a copyleft agreement.
In particular, the HESSLA contains objectives on security standards (section 9), the adherence of the use of the software to respecting human rights, political freedom and privacy standards (section 10), as well as special terms on the use of the software by governmental entities and governmental persons (section 14).
For the purpose of including UMTSkeeper or portions thereof in GNU GPL licensed projects, UMTSkeeper is also licensed under the GPL. You may distribute UMTSkeeper or derivatives under the GNU GPL, provided that your distribution is also subject to the HESSLA.


UMTSkeeper is free software: you can redistribute it and/or modify it under the terms of the Hacktivismo Enhanced-Source Software License Agreement (HESSLA) as published by Hacktivismo, either version 1, or prior, of the License, or (at your option) any later version.
By using UMTSkeeper, you express that you read and understood this license agreement, and that you are a Qualified Licensee as laid out in section 0.8, at the time you use UMTSkeeper, meaning that you will not use this software for infringement of human rights or the right to privacy. You will not use this software for surveillance purposes or to otherwise spy on people, neither for doing any harm to a human being.
See the Hacktivismo Enhanced-Source Software License Agreement (HESSLA) at for more details.


UMTSkeeper is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
See the GNU General Public License for more details:


This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

And this should be common sense:
Above statement includes additional charges you may receive from your operator by using this program, defects to your SIM card including but not limited to being PIN blocked, defects on your hardware, 3G service abuse ban etc. USE WITH CARE. The author of this program or authors of any of its dependencies have no responsibility for what may happen to you.

The author is not related in any way with any of the companies, being operators or modem manufacturers, other than being a customer to some of them. Logos and trademarks mentioned by this package belong to their respective owners.