WS2012 Dynamic Access Control Overview and Tips

You already own a PABX that you are not yet ready to replace fully with Lync but would like to integrate your PABX to Lync and leverage the most out of Lync as well as your legacy or new PABX. What options do you have? Why are some better than others ? What is supported? Come and find out what others around the world are doing.
Hi,
You may also check this video on what PABX is. It is based on Ozeki Phone System XE and it fairly explains PABX and VoIP:
http://www.ozekiphone.com/what-is-pabx-private-automated-branch-exchange-311.html
BR