What does it mean when calls are default routed?

When calls are default routed, it means that in circumstances where there is a failure in the normal routing channels, all call traffic is instead directed through a designated routing path, often referred to as the tandem. This ensures that calls can still be processed even when the primary routing method fails. In telecommunications, this scenario typically occurs when there is a technical issue or a switching failure that prevents the normal delivery of calls.

By default routing the calls through the affected tandem, the system maintains connectivity and service continuity, allowing calls to still be completed rather than being dropped or left unhandled. This method helps manage unexpected issues efficiently and ensures that callers can still reach the appropriate destination despite underlying problems in the network. Thus, it serves as a fallback mechanism to keep communication lines open during operational disruptions.