Docker image based on Ubuntu 16.04 (xenial) with python 2, PJSIP, and SIP Simple for testing VOIP PBX systems.
sip-settings -a add 6000@example secret
sip-settings -a set 6000@example sip.outbound_proxy="pbx.local:5061;transport=tls"
sip-register -s -j -a 6000@example