Dear Osmocom community,
during recent years we have developed a quite extensive set of test suites
for virtually all interfaces on all protocol levels of our 2G stack, and
recently even extended at least with some 3G IuCS coverage.
Those test suites are considerably valuable for testing any kind of
implementation of 2G / 3G network elements, even beyond Osmocom. I'm a
bit worried that they might be used to test proprietary implementations,
which would bring no value to growing FOSS in mobile communications.
Whether we license the test suites under GPL or AGPL doesn't actually
change much here: Imagine "EvilCorp" developing a BSC, using our test
suites against it. They neither distribute the test suite, nor do they
provide "access over a network" to it, an hence they could keep any
modifications/extensions/derivatives private without having to
contribute those back.
I think this is problematic. We develop those test suites because we
care about having well-tested FOSS in cellular communications, whether
Osmocom or other FOSS projects. I certainly don't want to spend my
spare time, or invest sysmocom resources towards improving the test
coverage of any non-FOSS implementations. If such users are out there,
they should at the very least contribute to the development effort in
one way (code) or another (funding).
For 2G/3G, I think this discussion is quite theoretical, as there is
unlikely anyone else implementing those old technologies in proprietary
systems - Osmocom is probably typically the latest player in the market
to do so.
However, as I'm currently working on a first set of TTCN3 tests for
testing a LTE MME (initially attacing to S1 and SGs), I'm wondering if
we should continue to release related code under traditional copyleft
One idea would be to have a license that permits the use of the test
suites to test only FOSS software. In theory, that would mean that all
projects we care about (such as currently srsLTE, nextepc, OAI EPC, ...)
could use the test suites to test their software. On the other hand,
if some vendor of proprietary MME/EPC software would want to [legally]
use the tests, they would need to obtain a different (paid) license to
the test suite. Of course they could simply ignore the license and we'd
have little chance to learn about it - but I would argue most proper
companies typically would obtain a license if they used some software
they knew they had to license.
This is a very double-edged sword. Drafting such a new license would
cause license proliferation, which is always bad. It also raises
quesetions of license compatibility with e.g. some of our common
existing 'library' code that would need to be investigated. Finally, it
also means that we'd no longer be writing "free software" nor "open
source", as the respective relevant definitions always require "non
discriminatory use for any purpose", which would no longer be the case
This is currently an early stage brainstorming. Now is the right point
in time to talk about this, before we release any LTE/EPC related tests.
Let me know if you have any thoughts to share. While I'm cross-posting
this to openbsc@ and nextepc@ lists, pleaes follow-up-to
openbsc(a)lists.osmocom.org, as that's the main Osmocom mailing list and
we don't have any specifically only for the test suites.
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
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