When configuring the internal and external web services for a Director, options exist to define the listening ports and the published ports. The differences between the two are outlined here:
• Listening ports—Ports that the IIS services bind to on the Lync Server.
• Published ports—Ports used by clients to access the services. These ports might 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. However, because the external web services use a separate IIS site, they need to run on alternate ports so that they do not conflict with the internal web services. In a default scenario, ...