On 12/03/15 06:16, Alex Balashov wrote:
I am also not at all an expert in GPL licencing
or IP, but would like
to add that any customisation you make specifically for the purpose of
interacting with a billing server or other external application is
likely to take the form of a Kamailio module, rather than
modifications to the existing Kamailio modules, the Kamailio core, or
any other part of the stock code tree.
As far as I know, under the GPL--broadly speaking, for I certainly
don't know or remember the specifics--modules get different treatment
than modifications per se.
As far sa I know, if you can stick your code into [a] completely
self-contained module(s) (and given what you've said about what
specifically you want to accomplish, it seems to me that you
absolutely can) that interact(s) with Kamailio using its module APIs
and requires no modifications to Kamailio itself, it's not subject to
the same licence constraints as modifications per se.
Please do not take my advice as stated, and consult a competent
software/IP attorney.
Modules have to be written in a GPLv2 compatible license,
because GPLv2
is 'viral' when linking the code, given that a module is using functions
from core. If you do communication via socket/etc. with a different
application, that application doesn't have to be GPLv2 compatible.
I recommend
you to ask to FSF.
It is possible even when communicating via sockets to need to release
your code under GPL.
In my point of view the difference is if your program works OK as a
standalone application or if it needs the other
GPLed application to work. That works to defeat some ways to cheat GPL
philosophy.