[asterisk-dev] 13 November, 2012 New SIP stack update

[Saúl Ibarra Corretgé]

Hi,

> Hi Saúl,
>
> I'd be interested to hear your feelings about pjsip/python-sipsimple
>
> For example,
>
> - why did you end up keeping patches locally, was it awkward to work
> with upstream, or license issues, or something else?
>

Disclaimer: What I'm sharing here are my personal thoughts and 
experience :-)

It's mostly that not everything we do can be applied upstream. We have 
advanced reINVITE handling, but for most PJSUA users it's not useful, so 
the patch has been sitting there for years. We also embed the WebRTC 
AEC. And there are some APIs we broke because of how we interact with 
the library from Python. There is probably more which I don't recall 
from the top of my head.

On top of that, PJSIP's design is not modular in that it doesn't 
dynamically load modules such as codecs at runtime, everything is 
embedded, so I fail to see how a single build would fit all.

> - would you consider making a fork based on your patches and sharing it
> with Asterisk as a standalone library?
>

If it benefits both projects, sure. We currently use the 1.0 branch but 
plan to upgrade to 2.0 and when we do that we'll fork the project 
properly and have it as a build time dependency. This saves a lot of 
build time, and we are not constantly changing our PJSIP tree anyway.

> - Or if Asterisk potentially went with reSIProcate, would you also
> potentially have the resources to change python-sipsimple to use
> reSIProcate?  I understand such change wouldn't happen quickly, of course
>

I don't see that happening, it would be too much work for very little to 
no gain.

> - same for Sofia SIP - if Asterisk uses Sofia and modernizes it, would
> you be tempted to use it in place of your current solution?
>

PJSIP provides us with a media library, codecs and so on. Asterisk 
doesn't need this, but python-sipsimple does. So if we'd change for 
Sofia, we would need to get a media library and make them work together.

IMHO, currently PJSIP is the most complete SIP and media library out 
there, but since Asterisk doesn't need the media parts other libraries 
such as Sofia or reSIProcate are good candidates.


Regards,

-- 
Saúl Ibarra Corretgé
http://saghul.net/blog | http://about.me/saghul