The OAS Service communicates with other OAS Services and local and remote .NET applications, Excel Workbooks, and OPCSystems.NET OPC Servers over TCP port. The default TCP port number that Open Automation Software uses is 58727. If you have a firewall simply add this port number in the exceptions list. The TCP port is adjustable using the Configure OAS application under Configure-Options as the TCP Port Number. You can also set the TCPPortNumber property in all .NET controls, Excel Workbooks, and OPCSystems.NET OPC Server.
To add a port to the exceptions list select Control Panel-Windows Firewall, then the Exceptions Tab. Use the Add Port button to add the TCP Port 58727 for both inbound and outbound traffic.
For remote connections you can either use a Network Node name, IP Address, or registered Internet domain name of the remote nodes.
Communications to web applications for Web HMI, Web Trend, Web Alarm, and REST API are performed by default through TCP Port 58725. This can be changed under Configure-Options-Networking.