After a bit of tweaking, CL-PJSIP now supports basic PJSUA API. PJSUA aggregates much of PJSIP functionality in a handful of structures and protocol methods. This simplifies application side a lot: one can get by with just a few lines of setup code and a couple callbacks. From Lisp perspective it also reduces the used FFI surface to a stable, generic interface. This ought to improve long term compatibility with PJSIP own revisions.
I refer to cl-pjsua-demo.lisp in the library for a short sample. Load the demo system and try (cl-pjsip::run-pjsua "sip:411@ideasip.com") for a quick test against a voice menu directory. It was tested on Linux x86_64 with CCL 11.1 and Allegro 10.1 beta. It however eventually crashes with floating point exception on SBCL.