Bro IDS is a popular open source network analysis platform. A key feature of Bro IDS is the custom BRO language that allows you to write scripts to enhance the functionality of the platform. Trisul Network Analytics is also a platform that can be extended by writing scripts. This page introduces the Trisul Scripting API for those who are already familiar with Bro IDS scripting.

Trisul is built from ground up to be full streaming analytics platform - database included. In Trisul, you work primarily with metrics and also other data types like resources, flows, documents, graphs. We will get to them later. This can be a bit confusing to Bro scripters who focus on generating logs.

To illustrate with an example.

Say you are calculating TLS Fingerprints from network traffic

• In Bro, you might write scripts to add the fingerprint to the connection/flow log.
• In Trisul, your approach would be to create a new counter group for TLS Fingerprints and count each print there. You can also mark the flows like Bro, or create graph edges, but the main focus is on metrics.

A second architectural difference is : In Trisul, you can script either the packet processing stream or the analytics stream. We call these two streams the Frontend (Fastpath) or the Backend (slowpath). The Frontend / Fastpath scripts work on packets and reassembled payloads, and the Backend scripts work on objects like traffic metrics for a particular entity, Top-K, flows, resources, etc. The two pipelines can talk to each other using a messaging API.