Twincast¶

Twincast is a resilience pattern where the same live feed is ingested simultaneously over two independent paths: primary and backup. The platform monitors both delivery paths and can use the backup when the primary degrades.

How Twincast works¶

In a typical setup one source feeds two independent ingest paths; the system compares their state and uses the working stream.

flowchart LR
    source["Source"] --> primary["Primary ingest"]
    source --> backup["Backup ingest"]
    primary --> origin["origin"]
    backup --> origin

Under normal conditions the primary path is preferred. If it fails, the system can switch to backup while keeping the broadcast going.

An important limitation: primary and backup ingest independently, so frame timestamps and video GOP structure are not synchronized between them. Failover between primary and backup is therefore less seamless than in modes where both paths share aligned stream structure.

When to use it¶

Twincast is especially useful when:

• you run studio or business-critical live channels;
• you ingest an important external source;
• even a few seconds of outage is undesirable;
• you need continuous visibility into primary and backup inputs.

What this scenario provides¶

Benefits of Twincast:

• redundancy for the whole ingest path, not only the server;
• ongoing monitoring of primary and backup;
• fast switch to the working path;
• lower risk of interruption from partial hardware or signal failure.

Limitations and requirements¶

For a correct Twincast deployment, consider:

• two independent ingest paths;
• clear identification of primary vs. backup;
• monitoring of quality and status on both paths;
• no timestamp/GOP alignment between primary and backup;
• rules for automatic or manual switching between them.