Rocket Terminal Emulator

How does the Rocket web emulator connect to a client’s mainframe computer? Does this software require that an EXTERNAL Rocket server (located in the CLOUD or somewhere else) must be configured with appropriate firewall and network changes on the client’s network infrastructure in order to connect to the secure location that hosts the client’s mainframe?

Or does this browser-base software get installed within the client’s browser system on the client’s PC and then relies on the client to configure the connection to the client’s mainframe?

Rocket BlueZone Web is server based and uses a centralised web service to provides authorised users with suitable browsers access to any host they can connect to (using VT, 3270, TN5250). A Cloud or on-prem. server could be used to host the web service.
Rocket BlueZone Web is a terminal emulator that operates in modern web browsers on most operating systems and mobile devices, using JavaScript and HTML5. The BlueZone Web server connects the web-based client terminal emulator to the terminal host.
I hope this helps.