[asterisk-dev] Idea for GSoC: Support of PRACK in Asterisk

[John Todd]

On Mar 24, 2009, at 5:25 PM, Kevin P. Fleming wrote:

> Nic Bellamy wrote:
>
>> A question for the Digium guys: what kind of license would be  
>> required
>> in order to use a third-party SIP library in a new SIP stack? Would  
>> an
>> LGPL library be usable?
>
> I recently (as in a few months ago) went through the exercise of  
> trying
> to use the Sofia stack's SDP parser/generator in chan_sip. It wasn't
> that hard to use, and it worked well.
>
> However, since it is licensed under the LGPL, incorporating the Sofia
> code *into* chan_sip won't work, as it doesn't fly with commercial
> licensing of Asterisk. *Linking* to an LGPL library outside Asterisk,
> though, is acceptable. In the case of the Sofia stack, this wasn't
> practical, because it's not widely packaged by Linux distributions, so
> it would be an inconvenience for users to have to download it from  
> some
> place, compile it and install it just to have SIP support in Asterisk.
> Conversely, if we distributed it as part of Asterisk, even though it
> might be compiled and installed separately, we'd risk infringing on  
> the
> 'spirit' of the LGPL by just using a build-time split to try to  
> avoid it.



Would incorporation of download/install of Sofia into the "make"  
process be unwieldy?  I could see that potentially as a "make  
menuselect" option that is selected by the administrator at the time  
of compile.  Or as suggested, something similar to the get_ilbc script.

JT

---
John Todd                       email:jtodd at digium.com
Digium, Inc. | Asterisk Open Source Community Director
445 Jan Davis Drive NW -  Huntsville AL 35806  -   USA
direct: +1-256-428-6083         http://www.digium.com/