My answer to this open letter is:
AG Projects developed a NAT traversal solution for SER and released
the source code under GPL license. The architecture, capabilities and
functionality of the software bares no resemblance with existing
nathelper/rtpproxy software.
- Local or remote installation
- Load balancing and redundancy using DNS SRV records
- Handles video or multiple audio streams
- Suports chained Media proxies and other SBCs
- Display active sessions from multiple servers
- Accounting of network traffic
- Independent of SER version
While AG Projects software achieves the purpose "NAT traversal", the
way we have achieved this does not justify Porta One to claim copyright
about the code.
Adrian
On 25 Mar 2004, at 00:01, Maxim Sobolev wrote:
Folks,
Unfortunately, all our attempts to solve mediaproxy copyright issue
have failed. AG Projects rejected to put due credit to Porta into it.
The AG confirms that all ideas in mediaproxy module came from the
nathelper module, but refuses to include due respect to Porta.
I think that it just have to be solved somehow, since for example, we,
Porta Software, always have been respecting others' copyrights and
licenses. While we use SER, Vodida B2BUA, FreeBSD and quite few other
free software components in our commercial solutions we never pretend
to our customers that we have written or invented any of them no
matter how deeply we have to rewrite something to fit our needs. We
provide full source code including our own modifications to our
customers when the license requires that.
Apart from that we always try to return our modifications and
enhancements back to community. Excellent example is nathelper module
and RTP proxy. While we could keep it in-house, we opted to make it
available to the whole community under liberal GPL license.
Unfortunately, folks like AG Projects, who don't have the aspiration
to do something innovative, try to use somebody's else work to cash on
it. This unfortunately happened with nathelper/rtpproxy. Once they had
seen that those extensions are in demand they immediately released
their own version of RTP proxy with better portability and some
bugfixes but under their commercial license which prevented any free
commercial use of it. Since RTP proxy is distributed under BSD-like
license, we decided that it is not necessary to make any noise about
it.
But probably it didn't went as smooth as they had hoped, bugs in
original RTP proxy were identified and fixed quickly, so that there
probably were not that many customers who wanted to buy AG's version.
Then they decided to cash on publicity: write GPL'ed module based on
nathelper with some enhancements, but pretend that they hold a full
copyright on this module. So that they can say loudly that they have
invented it and can sell it under commercial license if they want
without taking Porta who did the initial work into account. They found
a good excuse for a separating their module out: I had asked them to
send their patch to me before committing change into a nathelper
module. Any experienced open source/free software person can confirms
that such peer-review practice is common in open source projects, but
AG took an offense. It was just an excuse in my opinion.
OK, once their mediaproxy module had been released, I read its source
code and found that in many places it bears "strange" resemblance to
the nathelper. However, original nathelper copyright was striped and
replaced with AG's copyright. I reported this fact to them, asking to
put due Porta's copyright back, but they said that they have to
investigate this question.
After several days they replied that they had written mediaproxy
module from scratch and there was no code taken verbatim from the
nathelper module into mediaproxy module and asked me to show such
piece of code. However, when I have shown them such piece of code they
quickly responded (in private) that they would take this code out. But
my main point was not to show some particular piece of code, but to
show that mediaproxy module is just modifiend nathelper module.
Modified to the degree when it is hard to see original code, but still
"derived work" in legal terms.
Moreover, they do confirm that they used nathelper source code as a
reference for their work. In my opinion this gives us sufficient right
to claim copyright on derived work.
That's the whole story as we see it. Our legal department is currently
investigating if the matters are sufficient enough for suing AG for
copyright infringement. However, whatever they decide, I must say the
following:
- If folks like AG are tolerated by a community it will seriously
reduce our (and probably others') incentive to release source code as
free software. Respect is the only gain we as a company have from
releasing our code/ideas as free software, if there will be many folks
like AG, who will take our code/ideas, obfuscate it and say that they
are the authors we won't get any respect. Obviously in such world we
are better off to keep our code/ideas closed.
- I am really frustrated by their "embrace and extend" tactics. This
is the first time in my long free software life when somebody does
something like that with my code/ideas.
Regards,
Maxim Sobolev
Director of Product Management
Porta Software Ltd
_______________________________________________
Serdev mailing list
serdev(a)lists.iptel.org
http://lists.iptel.org/mailman/listinfo/serdev