Recent blog entries for LaForge

Power-cycling a USB port should be simple, right?

Every so often I happen to be involved in designing electronics equipment that's supposed to run reliably remotely in inaccessible locations,without any ability for "remote hands" to perform things like power-cycling or the like. I'm talking about really remote locations, possible with no but limited back-haul, and a very high cost of ever sending somebody there for remote maintenance.

Given that a lot of computer peripherals (chips, modules, ...) use USB these days, this is often some kind of an embedded ARM (rarely x86) SoM or SBC, which is hooked up to a custom board that contains a USB hub chip as well as a line of peripherals.

One of the most important lectures I've learned from experience is: Never trust reset signals / lines, always include power-switching capability. There are many chips and electronics modules available on the market that have either no RESET, or even might claim to have a hardware RESET line which you later (painfully) discover just to be a GPIO polled by software which can get stuck, and hence no way to really hard-reset the given component.

In the case of a USB-attached device (even though the USB might only exist on a circuit board between two ICs), this is typically rather easy: The USB hub is generally capable of switching the power of its downstream ports. Many cheap USB hubs don't implement this at all, or implement only ganged switching, but if you carefully select your USB hub (or in the case of a custom PCB), you can make sure that the given USB hub supports individual port power switching.

Now the next step is how to actually use this from your (embedded) Linux system. It turns out to be harder than expected. After all, we're talking about a standard feature that's present in the USB specifications since USB 1.x in the late 1990ies. So the expectation is that it should be straight-forward to do with any decent operating system.

I don't know how it's on other operating systems, but on Linux I couldn't really find a proper way how to do this in a clean way. For more details, please read my post to the linux-usb mailing list.

Why am I running into this now? Is it such a strange idea? I mean, power-cycling a device should be the most simple and straight-forward thing to do in order to recover from any kind of "stuck state" or other related issue. Logical enabling/disabling of the port, resetting the USB device via USB protocol, etc. are all just "soft" forms of a reset which at best help with USB related issues, but not with any other part of a USB device.

And in the case of e.g. an USB-attached cellular modem, we're actually talking about a multi-processor system with multiple built-in micro-controllers, at least one DSP, an ARM core that might run another Linux itself (to implement the USB gadget), ... - certainly enough complex software that you would want to be able to power-cycle it...

I'm curious what the response of the Linux USB gurus is.

Syndicated 2017-05-23 22:00:00 from LaForge's home page

Overhyped Docker

Overhyped Docker missing the most basic features

I've always been extremely skeptical of suddenly emerging over-hyped technologies, particularly if they advertise to solve problems by adding yet another layer to systems that are already sufficiently complex themselves.

There are of course many issues with containers, ranging from replicated system libraries and the basic underlying statement that you're giving up on the system packet manager to properly deal with dependencies.

I'm also highly skeptical of FOSS projects that are primarily driven by one (VC funded?) company. Especially if their offering includes a so-called cloud service which they can stop to operate at any given point in time, or (more realistically) first get everybody to use and then start charging for.

But well, despite all the bad things I read about it over the years, on one day in May 2017 I finally thought let's give it a try. My problem to solve as a test balloon is fairly simple.

My basic use case

The plan is to start OsmoSTP, the m3ua-testtool and the sua-testtool, which both connect to OsmoSTP. By running this setup inside containers and inside an internal network, we could then execute the entire testsuite e.g. during jenkins test without having IP address or port number conflicts. It could even run multiple times in parallel on one buildhost, verifying different patches as part of the continuous integration setup.

This application is not so complex. All it needs is three containers, an internal network and some connections in between. Should be a piece of cake, right?

But enter the world of buzzword-fueled web-4000.0 software-defined virtualised and orchestrated container NFW + SDN vodoo: It turns out to be impossible, at least not with the preferred tools they advertise.

Dockerfiles

The part that worked relatively easily was writing a few Dockerfiles to build the actual containers. All based on debian:jessie from the library.

As m3ua-testsuite is written in guile, and needs to build some guile plugin/extension, I had to actually include guile-2.0-dev and other packages in the container, making it a bit bloated.

I couldn't immediately find a nice example Dockerfile recipe that would allow me to build stuff from source outside of the container, and then install the resulting binaries into the container. This seems to be a somewhat weak spot, where more support/infrastructure would be helpful. I guess the idea is that you simply install applications via package feeds and apt-get. But I digress.

So after some tinkering, I ended up with three docker containers:

  • one running OsmoSTP
  • one running m3ua-testtool
  • one running sua-testtool

I also managed to create an internal bridged network between the containers, so the containers could talk to one another.

However, I have to manually start each of the containers with ugly long command line arguments, such as docker run --network sigtran --ip 172.18.0.200 -it osmo-stp-master. This is of course sub-optimal, and what Docker Services + Stacks should resolve.

Services + Stacks

The idea seems good: A service defines how a given container is run, and a stack defines multiple containers and their relation to each other. So it should be simple to define a stack with three services, right?

Well, it turns out that it is not. Docker documents that you can configure a static ipv4_address [1] for each service/container, but it seems related configuration statements are simply silently ignored/discarded [2], [3], [4].

This seems to be related that for some strange reason stacks can (at least in later versions of docker) only use overlay type networks, rather than the much simpler bridge networks. And while bridge networks appear to support static IP address allocations, overlay apparently doesn't.

I still have a hard time grasping that something that considers itself a serious product for production use (by a company with estimated value over a billion USD, not by a few hobbyists) that has no support for running containers on static IP addresses. that. How many applications out there have I seen that require static IP address configuration? How much simpler do setups get, if you don't have to rely on things like dynamic DNS updates (or DNS availability at all)?

So I'm stuck with having to manually configure the network between my containers, and manually starting them by clumsy shell scripts, rather than having a proper abstraction for all of that. Well done :/

Exposing Ports

Unrelated to all of the above: If you run some software inside containers, you will pretty soon want to expose some network services from containers. This should also be the most basic task on the planet.

However, it seems that the creators of docker live in the early 1980ies, where only TCP and UDP transport protocols existed. They seem to have missed that by the late 1990ies to early 2000s, protocols like SCTP or DCCP were invented.

But yet, in 2017, Docker chooses to

Now some of the readers may think 'who uses SCTP anyway'. I will give you a straight answer: Everyone who has a mobile phone uses SCTP. This is due to the fact that pretty much all the connections inside cellular networks (at least for 3G/4G networks, and in reality also for many 2G networks) are using SCTP as underlying transport protocol, from the radio access network into the core network. So every time you switch your phone on, or do anything with it, you are using SCTP. Not on your phone itself, but by all the systems that form the network that you're using. And with the drive to C-RAN, NFV, SDN and all the other buzzwords also appearing in the Cellular Telecom field, people should actually worry about it, if they want to be a part of the software stack that is used in future cellular telecom systems.

Summary

After spending the better part of a day to do something that seemed like the most basic use case for running three networked containers using Docker, I'm back to step one: Most likely inventing some custom scripts based on unshare to run my three test programs in a separate network namespace for isolated execution of test suite execution as part of a Jenkins CI setup :/

It's also clear that Docker apparently don't care much about playing a role in the Cellular Telecom world, which is increasingly moving away from proprietary and hardware-based systems (like STPs) to virtualised, software-based systems.

[1]https://docs.docker.com/compose/compose-file/#ipv4address-ipv6address
[2]https://forums.docker.com/t/docker-swarm-1-13-static-ips-for-containers/28060
[3]https://github.com/moby/moby/issues/31860
[4]https://github.com/moby/moby/issues/24170

Syndicated 2017-05-02 22:00:00 from LaForge's home page

OsmoDevCon 2017 Review

After the public user-oriented OsmoCon 2017, we also recently had the 6th incarnation of our annual contributors-only Osmocom Developer Conference: The OsmoDevCon 2017.

This is a much smaller group, typically about 20 people, and is limited to actual developers who have a past record of contributing to any of the many Osmocom projects.

We had a large number of presentation and discussions. In fact, so large that the schedule of talks extended from 10am to midnight on some days. While this is great, it also means that there was definitely too little time for more informal conversations, chatting or even actual work on code.

We also have such a wide range of topics and scope inside Osmocom, that the traditional ad-hoch scheduling approach no longer seems to be working as it used to. Not everyone is interested in (or has time for) all the topics, so we should group them according to their topic/subject on a given day or half-day. This will enable people to attend only those days that are relevant to them, and spend the remaining day in an adjacent room hacking away on code.

It's sad that we only have OsmoDevCon once per year. Maybe that's actually also something to think about. Rather than having 4 days once per year, maybe have two weekends per year.

Always in motion the future is.

Syndicated 2017-05-02 22:00:00 from LaForge's home page

Book on Practical GPL Compliance

My former gpl-violations.org colleague Armijn Hemel and Shane Coughlan (former coordinator of the FSFE Legal Network) have written a book on practical GPL compliance issues.

I've read through it (in the bath tub of course, what better place to read technical literature), and I can agree wholeheartedly with its contents. For those who have been involved in GPL compliance engineering there shouldn't be much new - but for the vast majority of developers out there who have had little exposure to the bread-and-butter work of providing complete an corresponding source code, it makes an excellent introductory text.

The book focuses on compliance with GPLv2, which is probably not too surprising given that it's published by the Linux foundation, and Linux being GPLv2.

You can download an electronic copy of the book from https://www.linuxfoundation.org/news-media/research/practical-gpl-compliance

Given the subject matter is Free Software, and the book is written by long-time community members, I cannot help to notice a bit of a surprise about the fact that the book is released in classic copyright under All rights reserved with no freedom to the user.

Considering the sensitive legal topics touched, I can understand the possible motivation by the authors to not permit derivative works. But then, there still are licenses such as CC-BY-ND which prevent derivative works but still permit users to make and distribute copies of the work itself. I've made that recommendation / request to Shane, let's see if they can arrange for some more freedom for their readers.

Syndicated 2017-05-01 22:00:00 from LaForge's home page

OsmoCon 2017 Review

It's already one week past the event, so I really have to sit down and write some rewview on the first public Osmocom Conference ever: OsmoCon 2017.

The event was a huge success, by all accounts.

  • We've not only been sold out, but we also had to turn down some last minute registrations due to the venue being beyond capacity (60 seats). People traveled from Japan, India, the US, Mexico and many other places to attend.
  • We've had an amazing audience ranging from commercial operators to community cellular operators to professional developers doing work relate to osmocom, academia, IT security crowds and last but not least enthusiasts/hobbyists, with whom the project[s] started.
  • I've received exclusively positive feedback from many attendees
  • We've had a great programme. Some part of it was of introductory nature and probably not too interesting if you've been in Osmocom for a few years. However, the work on 3G as well as the current roadmap was probably not as widely known yet. Also, I really loved to see Roch's talk about Running a commercial cellular network with Osmocom software as well as the talk on Facebook's OpenCellular BTS hardware and the Community Cellular Manager.
  • We have very professional live streaming + video recordings courtesy of the C3VOC team. Thanks a lot for your support and for having the video recordings of all talks online already at the next day after the event.

We also received some requests for improvements, many of which we will hopefully consider before the next Osmocom Conference:

  • have a multiple day event. Particularly if you're traveling long-distance, it is a lot of overhead for a single-day event. We of course fully understand that. On the other hand, it was the first Osmocom Conference, and hence it was a test balloon where it was initially unclear if we'll be able to get a reasonable number of attendees interested at all, or not. And organizing an event with venue and talks for multiple days if in the end only 10 people attend would have been a lot of effort and financial risk. But now that we know there are interested folks, we can definitely think of a multiple day event next time
  • Signs indicating venue details on the last meters. I agree, this cold have been better. The address of the venue was published, but we could have had some signs/posters at the door pointing you to the right meeting room inside the venue. Sorry for that.
  • Better internet connectivity. This is a double-edged sword. Of course we want our audience to be primarily focused on the talks and not distracted :P I would hope that most people are able to survive a one day event without good connectivity, but for sure we will have to improve in case of a multiple-day event in the future

In terms of my requests to the attendees, I only have one

  • Participate in the discussions on the schedule/programme while it is still possible to influence it. When we started to put together the programme, I posted about it on the openbsc mailing list and invited feedback. Still, most people seem to have missed the time window during which talks could have been submitted and the schedule still influenced before finalizing it
  • Register in time. We have had almost no registrations until about two weeks ahead of the event (and I was considering to cancel it), and then suddenly were sold out in the week ahead of the event. We've had people who first booked their tickets, only to learn that the tickets were sold out. I guess we will introduce early bird pricing and add a very expensive last minute ticket option next year in order to increase motivation to register early and thus give us flexibility regarding venue planning.

Thanks again to everyone involved in OsmoCon 2017!

Ok, now, all of you who missed the event: Go to https://media.ccc.de/c/osmocon17 and check out the recordings. Have fun!

Syndicated 2017-04-30 22:00:00 from LaForge's home page

Things you find when using SCTP on Linux

Observations on SCTP and Linux

When I was still doing Linux kernel work with netfilter/iptables in the early 2000's, I was somebody who actually regularly had a look at the new RFCs that came out. So I saw the SCTP RFCs, SIGTRAN RFCs, SIP and RTP, etc. all released during those years. I was quite happy to see that for new protocols like SCTP and later DCCP, Linux quickly received a mainline implementation.

Now most people won't have used SCTP so far, but it is a protocol used as transport layer in a lot of telecom protocols for more than a decade now. Virtually all protocols that have traditionally been spoken over time-division multiplex E1/T1 links have been migrated over to SCTP based protocol stackings.

Working on various Open Source telecom related projects, i of course come into contact with SCTP every so often. Particularly some years back when implementing the Erlang SIGTAN code in erlang/osmo_ss7 and most recently now with the introduction of libosmo-sigtran with its OsmoSTP, both part of the libosmo-sccp repository.

I've also hard to work with various proprietary telecom equipment over the years. Whether that's some eNodeB hardware from a large brand telecom supplier, or whether it's a MSC of some other vendor. And they all had one thing in common: Nobody seemed to use the Linux kernel SCTP code. They all used proprietary implementations in userspace, using RAW sockets on the kernel interface.

I always found this quite odd, knowing that this is the route that you have to take on proprietary OSs without native SCTP support, such as Windows. But on Linux? Why? Based on rumors, people find the Linux SCTP implementation not mature enough, but hard evidence is hard to come by.

As much as it pains me to say this, the kind of Linux SCTP bugs I have seen within the scope of our work on Osmocom seem to hint that there is at least some truth to this (see e.g. https://bugzilla.redhat.com/show_bug.cgi?id=1308360 or https://bugzilla.redhat.com/show_bug.cgi?id=1308362).

Sure, software always has bugs and will have bugs. But we at Osmocom are 10-15 years "late" with our implementations of higher-layer protocols compared to what the mainstream telecom industry does. So if we find something, and we find it even already during R&D of some userspace code, not even under load or in production, then that seems a bit unsettling.

One would have expected, with all their market power and plenty of Linux-based devices in the telecom sphere, why did none of those large telecom suppliers invest in improving the mainline Linux SCTP code? I mean, they all use UDP and TCP of the kernel, so it works for most of the other network protocols in the kernel, but why not for SCTP? I guess it comes back to the fundamental lack of understanding how open source development works. That it is something that the given industry/user base must invest in jointly.

The leatest discovered bug

During the last months, I have been implementing SCCP, SUA, M3UA and OsmoSTP (A Signal Transfer Point). They were required for an effort to add 3GPP compliant A-over-IP to OsmoBSC and OsmoMSC.

For quite some time I was seeing some erratic behavior when at some point the STP would not receive/process a given message sent by one of the clients (ASPs) connected. I tried to ignore the problem initially until the code matured more and more, but the problems remained.

It became even more obvious when using Michael Tuexen's m3ua-testtool, where sometimes even the most basic test cases consisting of sending + receiving a single pair of messages like ASPUP -> ASPUP_ACK was failing. And when the test case was re-tried, the problem often disappeared.

Also, whenever I tried to observe what was happening by meas of strace, the problem would disappear completely and never re-appear until strace was detached.

Of course, given that I've written several thousands of lines of new code, it was clear to me that the bug must be in my code. Yesterday I was finally prepare to accept that it might actually be a Linux SCTP bug. Not being able to reproduce that problem on a FreeBSD VM also pointed clearly into this direction.

Now I could simply have collected some information and filed a bug report (which some kernel hackers at RedHat have thankfully invited me to do!), but I thought my use case was too complex. You would have to compile a dozen of different Osmocom libraries, configure the STP, run the scheme-language m3ua-testtool in guile, etc. - I guess nobody would have bothered to go that far.

So today I tried to implement a test case that reproduced the problem in plain C, without any external dependencies. And for many hours, I couldn't make the bug to show up. I tried to be as close as possible to what was happening in OsmoSTP: I used non-blocking mode on client and server, used the SCTP_NODELAY socket option, used the sctp_rcvmsg() library wrapper to receive events, but the bug was not reproducible.

Some hours later, it became clear that there was one setsockopt() in OsmoSTP (actually, libosmo-netif) which enabled all existing SCTP events. I did this at the time to make sure OsmoSTP has the maximum insight possible into what's happening on the SCTP transport layer, such as address fail-overs and the like.

As it turned out, adding that setsockopt for SCTP_FLAGS to my test code made the problem reproducible. After playing around which of the flags, it seems that enabling the SENDER_DRY_EVENT flag makes the bug appear.

You can find my detailed report about this issue in https://bugzilla.redhat.com/show_bug.cgi?id=1442784 and a program to reproduce the issue at http://people.osmocom.org/laforge/sctp-nonblock/sctp-dry-event.c

Inside the Osmocom world, luckily we can live without the SENDER_DRY_EVENT and a corresponding work-around has been submitted and merged as https://gerrit.osmocom.org/#/c/2386/

With that work-around in place, suddenly all the m3ua-testtool and sua-testtool test cases are reliably green (PASSED) and OsmoSTP works more smoothly, too.

What do we learn from this?

Free Software in the Telecom sphere is getting too little attention. This is true even those small portions of telecom relevant protocols that ended up in the kernel like SCTP or more recently the GTP module I co-authored. They are getting too little attention in development, even more lack of attention in maintenance, and people seem to focus more on not using it, rather than fixing and maintaining what is there.

It makes me really sad to see this. Telecoms is such a massive industry, with billions upon billions of revenue for the classic telecom equipment vendors. Surely, they would be able to co-invest in some basic infrastructure like proper and reliable testing / continuous integration for SCTP. More recently, we see millions and more millions of VC cash burned by buzzword-flinging companies doing "NFV" and "SDN". But then rather reimplement network stacks in userspace than to fix, complete and test those little telecom infrastructure components which we have so far, like the SCTP protocol :(

Where are the contributions to open source telecom parts from Ericsson, Nokia (former NSN), Huawei and the like? I'm not even dreaming about the actual applications / network elements, but merely the maintenance of something as basic as SCTP. To be fair, Motorola was involved early on in the Linux SCTP code, and Huawei contributed a long series of fixes in 2013/2014. But that's not the kind of long-term maintenance contribution that one would normally expect from the primary interest group in SCTP.

Finally, let me thank to the Linux SCTP maintainers. I'm not complaining about them! They're doing a great job, given the arcane code base and the fact that they are not working for a company that has SCTP based products as their core business. I'm sure the would love more support and contributions from the Telecom world, too.

Syndicated 2017-04-16 22:00:00 from LaForge's home page

SIGTRAN/SS7 stack in libosmo-sigtran merged to master

As I blogged in my blog post in Fabruary, I was working towards a more fully-featured SIGTRAN stack in the Osmocom (C-language) universe.

The trigger for this is the support of 3GPP compliant AoIP (with a BSSAP/SCCP/M3UA/SCTP protocol stacking), but it is of much more general nature.

The code has finally matured in my development branch(es) and is now ready for mainline inclusion. It's a series of about 77 (!) patches, some of which already are the squashed results of many more incremental development steps.

The result is as follows:

  • General SS7 core functions maintaining links, linksets and routes
  • xUA functionality for the various User Adaptations (currently SUA and M3UA supported)
    • MTP User SAP according to ITU-T Q.701 (using osmo_prim)
    • management of application servers (AS)
    • management of application server processes (ASP)
    • ASP-SM and ASP-TM state machine for ASP, AS-State Machine (using osmo_fsm)
    • server (SG) and client (ASP) side implementation
    • validated against ETSI TS 102 381 (by means of Michael Tuexen's m3ua-testtool)
    • support for dynamic registration via RKM (routing key management)
    • osmo-stp binary that can be used as Signal Transfer Point, with the usual "Cisco-style" command-line interface that all Osmocom telecom software has.
  • SCCP implementation, with strong focus on Connection Oriented SCCP (as that's what the A interface uses).
    • osmo_fsm based state machine for SCCP connection, both incoming and outgoing
    • SCCP User SAP according to ITU-T Q.711 (osmo_prim based)
    • Interfaces with underlying SS7 stack via MTP User SAP (osmo_prim based)
    • Support for SCCP Class 0 (unit data) and Class 2 (connection oriented)
    • All SCCP + SUA Address formats (Global Title, SSN, PC, IPv4 Address)
    • SCCP and SUA share one implementation, where SCCP messages are transcoded into SUA before processing, and re-encoded into SCCP after processing, as needed.

I have already done experimental OsmoMSC and OsmoHNB-GW over to libosmo-sigtran. They're now all just M3UA clients (ASPs) which connect to osmo-stp to exchange SCCP messages back and for the between them.

What's next on the agenda is to

  • finish my incomplete hacks to introduce IPA/SCCPlite as an alternative to SUA and M3UA (for backwards compatibility)
  • port over OsmoBSC to the SCCP User SAP of libosmo-sigtran
    • validate with SSCPlite lower layer against existing SCCPlite MSCs
  • implement BSSAP / A-interface procedures in OsmoMSC, on top of the SCCP-User SAP.

If those steps are complete, we will have a single OsmoMSC that can talk both IuCS to the HNB-GW (or RNCs) for 3G/3.5G as well as AoIP towards OsmoBSC. We will then have fully SIGTRAN-enabled the full Osmocom stack, and are all on track to bury the OsmoNITB that was devoid of such interfaces.

If any reader is interested in interoperability testing with other implementations, either on M3UA or on SCCP or even on A or Iu interface level, please contact me by e-mail.

Syndicated 2017-04-09 22:00:00 from LaForge's home page

OsmoCon 2017 Updates: Travel Grants and Schedule

/images/osmocon.png

April 21st is approaching fast, so here some updates. I'm particularly happy that we now have travel grants available. So if the travel expenses were preventing you from attending so far: This excuse is no longer valid!

Get your ticket now, before it is too late. There's a limited number of seats available.

OsmoCon 2017 Schedule

The list of talks for OsmoCon 2017 has been available for quite some weeks, but today we finally published the first actual schedule.

As you can see, the day is fully packed with talks about Osmocom cellular infrastructure projects. We had to cut some talk slots short (30min instead of 45min), but I'm confident that it is good to cover a wider range of topics, while at the same time avoiding fragmenting the audience with multiple tracks.

OsmoCon 2017 Travel Grants

We are happy to announce that we have received donations to permit for providing travel grants!

This means that any attendee who is otherwise not able to cover their travel to OsmoCon 2017 (e.g. because their interest in Osmocom is not related to their work, or because their employer doesn't pay the travel expenses) can now apply for such a travel grant.

For more details see OsmoCon 2017 Travel Grants and/or contact osmocon2017@sysmocom.de.

OsmoCon 2017 Social Event

Tech Talks are nice and fine, but what many people enjoy even more at conferences is the informal networking combined with good food. For this, we have the social event at night, which is open to all attendees.

See more details about it at OsmoCon 2017 Social Event.

Syndicated 2017-03-26 22:00:00 from LaForge's home page

Upcoming v3 of Open Hardware miniPCIe WWAN modem USB breakout board

Back in October 2016 I designed a small open hardware breakout board for WWAN modems in mPCIe form-factor. I was thinking some other people might be interested in this, and indeed, the first manufacturing batch is already sold out by now.

Instead of ordering more of the old (v2) design, I decided to do some improvements in the next version:

  • add mounting holes so the PCB can be mounted via M3 screws
  • add U.FL and SMA sockets, so the modems are connected via a short U.FL to U.FL cable, and external antennas or other RF components can be attached via SMA. This provides strain relief for the external antenna or cabling and avoids tearing off any of the current loose U.FL to SMA pigtails
  • flip the SIM slot to the top side of the PCB, so it can be accessed even after mounting the board to some base plate or enclosure via the mounting holes
  • more meaningful labeling of the silk screen, including the purpose of the jumpers and the input voltage.

A software rendering of the resulting v3 PCB design files that I just sent for production looks like this:

/images/mpcie-breakout-v3-pcb-rendering.png

Like before, the design of the board (including schematics and PCB layout design files) is available as open hardware under CC-BY-SA license terms. For more information see http://osmocom.org/projects/mpcie-breakout/wiki

It will take some expected three weeks until I'll see the first assembled boards.

Syndicated 2017-03-23 23:00:00 from LaForge's home page

Osmocom - personal thoughts

As I just wrote in my post about TelcoSecDay, I sometimes worry about the choices I made with Osmocom, particularly when I see all the great stuff people doing in fields that I previously was working in, such as applied IT security as well as Linux Kernel development.

History

When people like Dieter, Holger and I started to play with what later became OpenBSC, it was just for fun. A challenge to master. A closed world to break open and which to attack with the tools, the mindset and the values that we brought with us.

Later, Holger and I started to do freelance development for commercial users of Osmocom (initially basically only OpenBSC, but then OsmoSGSN, OsmoBSC, OsmoBTS, OsmoPCU and all the other bits on the infrastructure side). This lead to the creation of sysmocom in 2011, and ever since we are trying to use revenue from hardware sales as well as development contracts to subsidize and grow the Osmocom projects. We're investing most of our earnings directly into more staff that in turn works on Osmocom related projects.

NOTE

It's important to draw the distinction betewen the Osmocom cellular infrastructure projects which are mostly driven by commercial users and sysmocom these days, and all the many other pure juts-for-fun community projects under the Osmocom umbrella, like OsmocomTETRA, OsmocomGMR, rtl-sdr, etc. I'm focussing only on the cellular infrastructure projects, as they are in the center of my life during the past 6+ years.

In order to do this, I basically gave up my previous career[s] in IT security and Linux kernel development (as well as put things like gpl-violations.org on hold). This is a big price to pay for crating more FOSS in the mobile communications world, and sometimes I'm a bit melancholic about the "old days" before.

Financial wealth is clearly not my primary motivation, but let me be honest: I could have easily earned a shitload of money continuing to do freelance Linux kernel development, IT security or related consulting. There's a lot of demand for related skills, particularly with some experience and reputation attached. But I decided against it, and worked several years without a salary (or almost none) on Osmocom related stuff [as did Holger].

But then, even with all the sacrifices made, and the amount of revenue we can direct from sysmocom into Osmocom development: The complexity of cellular infrastructure vs. the amount of funding and resources is always only a fraction of what one would normally want to have to do a proper implementation. So it's constant resource shortage, combined with lots of unpaid work on those areas that are on the immediate short-term feature list of customers, and that nobody else in the community feels like he wants to work on. And that can be a bit frustrating at times.

Is it worth it?

So after 7 years of OpenBSC, OsmocomBB and all the related projects, I'm sometimes asking myself whether it has been worth the effort, and whether it was the right choice.

It was right from the point that cellular technology is still an area that's obscure and unknown to many, and that has very little FOSS (though Improving!). At the same time, cellular networks are becoming more and more essential to many users and applications. So on an abstract level, I think that every step in the direction of FOSS for cellular is as urgently needed as before, and we have had quite some success in implementing many different protocols and network elements. Unfortunately, in most cases incompletely, as the amount of funding and/or resources were always extremely limited.

Satisfaction/Happiness

On the other hand, when it comes to metrics such as personal satisfaction or professional pride, I'm not very happy or satisfied. The community remains small, the commercial interest remains limited, and as opposed to the Linux world, most players have a complete lack of understanding that FOSS is not a one-way road, but that it is important for all stakeholders to contribute to the development in terms of development resources.

Project success?

I think a collaborative development project (which to me is what FOSS is about) is only then truly successful, if its success is not related to a single individual, a single small group of individuals or a single entity (company). And no matter how much I would like the above to be the case, it is not true for the Osmocom cellular infrastructure projects. Take away Holger and me, or take away sysmocom, and I think it would be pretty much dead. And I don't think I'm exaggerating here. This makes me sad, and after all these years, and after knowing quite a number of commercial players using our software, I would have hoped that the project rests on many more shoulders by now.

This is not to belittle the efforts of all the people contributing to it, whether the team of developers at sysmocom, whether those in the community that still work on it 'just for fun', or whether those commercial users that contract sysmocom for some of the work we do. Also, there are known and unknown donors/funders, like the NLnet foundation for some parts of the work. Thanks to all of you, and clearly we wouldn't be where we are now without all of that!

But I feel it's not sufficient for the overall scope, and it's not [yet] sustainable at this point. We need more support from all sides, particularly those not currently contributing. From vendors of BTSs and related equipment that use Osmocom components. From operators that use it. From individuals. From academia.

Yes, we're making progress. I'm happy about new developments like the Iu and Iuh support, the OsmoHLR/VLR split and 2G/3G authentication that Neels just blogged about. And there's progress on the SIMtrace2 firmware with card emulation and MITM, just as well as there's progress on libosmo-sigtran (with a more complete SUA, M3UA and connection-oriented SCCP stack), etc.

But there are too little people working on this, and those people are mostly coming from one particular corner, while most of the [commercial] users do not contribute the way you would expect them to contribute in collaborative FOSS projects. You can argue that most people in the Linux world also don't contribute, but then the large commercial beneficiaries (like the chipset and hardware makers) mostly do, as are the large commercial users.

All in all, I have the feeling that Osmocom is as important as it ever was, but it's not grown up yet to really walk on its own feet. It may be able to crawl, though ;)

So for now, don't panic. I'm not suffering from burn-out, mid-life crisis and I don't plan on any big changes of where I put my energy: It will continue to be Osmocom. But I also think we have to have a more open discussion with everyone on how to move beyond the current situation. There's no point in staying quiet about it, or to claim that everything is fine the way it is. We need more commitment. Not from the people already actively involved, but from those who are not [yet].

If that doesn't happen in the next let's say 1-2 years, I think it's fair that I might seriously re-consider in which field and in which way I'd like to dedicate my [I would think considerable] productive energy and focus.

Syndicated 2017-03-21 18:00:00 from LaForge's home page

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