How do I establish a connection over the secured firewall and authenticate it to transmit PI data over the PI-Interface and PI Connector?
If it is in same domain then you can ask IT team open windows and network firewall to allow traffic from PI Interface server to PI Server (5450).
In case if you are in different domain then suggest creating a local account and domain account (similar) and configure windows credential manager.
In either case use PI API for integrated security on PI Interface server to enable windows authentication for interface instance.
Windows Security Configurations in Domains and Workgroups for the PI Data Archive
Retrieving data ...