Patent attributes
Methods, systems, and computer products facilitate access to historical data via a real-time tunnel within an architectural framework that encompasses an operational technology (OT) network, a de-militarized zone (DMZ), and an information technology (IT) network. Real-time data is retrieved from a data source using a first connector, which comprises a first tunneller, a first history-writer, and a first history-tunneller. The mechanisms involve interleaving real-time data and historical data over a first tunnel connection, a first firewall, and a second firewall by (a) executing pull replication of the historical data, (b) daisy-chaining the historical data, or (c) a combination of both (a) and (b). Subsequently, the real-time data is written to a first historian.