PJSIP Overview
Get Started
PJSUA2 Guide
pj::Endpoint
pj::Account
pj::Media
pj::Call
pj::Buddy
Specific Guides
API Reference & Samples
A general guide on how to reduce CPU utilization can be found here: FAQ-CPU utilization.
https://trac.pjsip.org/repos/wiki/FAQ#Footprint