Cisco Systems 

Cisco eStreamer (Event Streamer) is a client-server API that enables external applications to receive security event data from Cisco Secure Firewall Management Center (formerly Firepower Management Center). It streams intrusion events, connection events, file and malware events, and discovery data in real time to SIEM and analytics platforms. 

eStreamer provides a high-performance method for exporting Cisco firewall security data including intrusion alerts, network flow records, host and application discovery data, and correlation events. This integration enables security operations teams to correlate Cisco firewall intelligence with data from other security tools for comprehensive threat detection and incident investigation.