[joseph8th]

No, the projector is never connected to the internet. It's connected to a cinema server. In the case of Sony, it's always a Sony server. This is not usually connected to the internet either. Instead, the usual topology is to have a Theater Management System (TMS) that pre-ingests content in the form of Digital Cinema Packages (DCPs) and then propagates it to each auditorium's server.

This TMS is also not connected to the internet in most cases. Digital cinema is locked down tight as an ATM. Most theaters have pretty meager on-site IT, so email and thumb-drives and hard-drives still rule.

I work in cinema IoT including KDM and DCP delivery and ingestion to TMS or cinema server, and our solution is to have a separate agent inside the private cinema network that can broker communication with cinema devices like projectors, calibrators, and audio processors. Some of these have their own UIs in the local network, or if you've got the company VPN, but in general for monitoring we just rely on SNMP or server API.

The cinema servers are different. They all have APIs that provide varying levels of monitoring, control, and automation for the server, itself, as well as connected devices including limited monitoring and control of projectors and audio. They all support RDP or VNC, so if you're behind the same firewall you can get to their UI. Same with TMSes... they have UIs that you can access remotely, if you're on the company VPN.

But the projector itself? Never on the internet. It's "married" to the cinema server, and will only work with that particular server, based on their respective certs.

In Sony's case, it sounds like the projector certs have expired, so now they are invalid when used with the updated server certs.