I'm looking for a very simple way of answering a call placed down a SIP trunk. I don't need anything more than being able to answer the call when it rings and being able to detect when it has ended.
Does anyone have any good pointers to get me started? Ideally, I'd like to find some simple open-source C++ code that I could use as a basis, but any tutorials or other helpful links would also be appreciated.
PJSIP http://www.pjsip.org/
EDIT: Oh yeah. We tried a few, this one was the least heavy. The library was also good for us as we could use it in an embedded box (RTEMS), on Linux and Windows.
I can't remember the other SIP stack we used but it sucked. It leaked so much memory you had to just delete everything and reinstantiate the stack between calls, and the messages took FOREVER to traverse the stack.
If you are not tied to C++, you could try the Jain sip stack. This is open source and has good documentation/examples.