3CX Phone System requires a web server for several websites including the management console, phone provisioning and to tunnel updates to 3CX clients. This web server can run on an existing IIS installation or on a dedicated bundled Abyss web server. You will need to configure on which ports these websites will run. The ports for both HTTP and HTTPS can be configured.
When should you choose port 80 and 443?
If you haven’t got any other services running on port 80 or 443, the easiest and most practical selection is to select port 80 for HTTP and port 443 for HTTPS. This way you will not need to make any changes to your firewall.
DO NOT set port 443 for HTTP and port 80 for HTTPS, because firewalls will not work properly.
Do Not Use Ports Which are Blocked by Popular Browsers
Browsers block ports by default because they are either dangerous or they are popular ports. Make sure that you check the following lists and do not use ports which are included in these lists:
- Ports blocked for Internet Explorer: https://code.google.com/p/browsersec/wiki/Part2#Port_access_restrictions
- Ports blocked for Mozilla Firefox: http://www-archive.mozilla.org/projects/netlib/PortBanning.html#portlist
- Ports blocked in Google Chrome: https://code.google.com/p/browsersec/wiki/Part2#Port_access_restrictions
When should you select 5000/5001?
If you have other web applications running on ports 80 and 443, then you cannot choose these ports for 3CX. In these cases you can choose port 5000 for HTTP and port 5001 for HTTPS. These are the ports used by previous 3CX Phone System installations and we recommend use of these ports if you already have 3CX Phone System v12 or earlier running and do not want to reprovision your 3CX clients. We also recommend these ports if you are running other websites on IIS, such as an Exchange Server.
IMPORTANT NOTE: In previous versions of 3CX Phone System, the default port for HTTP was 5000 and for HTTPS was 5001. It is recommended that you KEEP these ports. If you change these ports, you will need to reprovision all your phone clients (Deskphones and 3CXPhone clients) to inform the clients of the port change.