I Built a Circuit Breaker for Phone Lines So Customers Never Hear Dead Air

Описание и применение

Создан телекоммуникационный «circuit breaker» для телефонных линий, который автоматически переключает вызовы на резервный оператор при сбое основного, сохраняя пользовательский опыт и доверие.

Задача

Phone lines fail, causing customers to hear dead air and lose calls, especially critical for banks, hospitals, and emergency services.

Результат

The circuit breaker ensures continuous voice service during carrier outages, maintaining customer trust with a brief outage announcement and preventing call loss.

Рабочий процесс

• 1. Detect suspicious transaction and initiate fraud alert call via primary carrier.
• 2. Monitor carrier webhooks for call outcomes (busy, no-answer, timeout).
• 3. Increment failure counter on each failure webhook.
• 4. Trip circuit breaker after threshold (default 3) and route new calls through backup carrier.
• 5. After cooldown, enter half-open state and probe primary carrier with a live call.
• 6. If probe succeeds, close breaker and route future calls to primary; otherwise keep open and continue using backup.

Доказательства

The system has two independent Telnyx Call Control connections. A router sits in front and watches for failure signals.

Источник

When failures accumulate — busy, no-answer, timeout — the breaker trips at a threshold and all new calls route through the backup connection.

Источник

The backup announcement doesn't hide the outage — it says "we're running on our backup systems right now."

Источник