When configuring the internal and external web services for a Director, options exist to define both the listening ports and the published ports. The differences between the two are outlined here:
• Listening Ports—Ports the IIS services will bind to on the Lync Server 2013 server.
• Published Ports—Ports used by clients to access the services. These can then be redirected by a load balancer, reverse proxy, or firewall to the listening port on a server.
In a default installation the internal web services are listening and published on ports 80 and 443, but because the external web services use a separate IIS site, they need to be running on an alternate port so as to not conflict with the internal web services. In a default ...