[SR-Users] Regd. Kamailio GPL

[Vicente Hernando]

On 03/13/2015 10:19 AM, Daniel-Constantin Mierla wrote:
>
> On 12/03/15 16:01, Vicente Hernando wrote:
>> On 03/12/2015 01:45 PM, Daniel-Constantin Mierla wrote:
>>> 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.
> By far not a lawyer, but as long as the communication is done via
> socket, it means the application runs alone, not requiring the other
> application to run at all. You can compare this situation like browser -
> web server communication, the relation between them is socket
> communication, but doesn't enforce that browser has to be gpl because
> the server is gpl.
IANAL either.

You are right in the web server - browser case, but it depends on the 
coupling of the two applications.

E.g: you could not create a socket interface for Kamailio to plug new 
propietary modules and distribute them under closed licenses
or  create a proprietary app that configures via socket a GPL 
application and without that the GPL application be unable to run.

Regards,
Vicente.
>
> Cheers,
> Daniel
>