--- title: "Line Health & Reliability — How CallsAround Stays Answerable | CallsAround" description: "How CallsAround keeps business lines answerable: conversational canary probes that test every line's agent around the clock, carrier-level dead-man failover below the AI stack, automatic recovery, and a public status page." lang: en json-ld: | [ { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "Can callers ever reach dead air?", "acceptedAnswer": { "@type": "Answer", "text": "It's designed out structurally. If the AI stack degrades, the number is switched to plain carrier call forwarding at the phone network — below our servers — so callers ring the business's backup phone directly. The failover mechanism does not depend on our infrastructure being healthy, which is the property that matters: the backstop works precisely when everything above it doesn't." } }, { "@type": "Question", "name": "What does the canary actually test?", "acceptedAnswer": { "@type": "Answer", "text": "It holds a real scripted conversation with each line's agent — the same path a customer's call takes — and asks to reach a human, then verifies the agent responds correctly, including making the right tool call. It exercises the full stack: telephony, the AI model, our dispatch engine, and the line's own configuration. A ping that checks 'server is up' would miss most real failure modes; a conversation can't." } }, { "@type": "Question", "name": "How fast is a failure detected and routed around?", "acceptedAnswer": { "@type": "Answer", "text": "Probes run around the clock on every line. Repeated consecutive failures — not a single blip — trip the failover, and detection-to-reroute is typically under ten minutes. Recovery is symmetric: once probes pass again, forwarding switches off automatically and the AI takes the line back. No human has to notice, decide, or flip anything at 3 AM." } }, { "@type": "Question", "name": "Do you publish an uptime number?", "acceptedAnswer": { "@type": "Answer", "text": "We publish something better: a live public status page driven by the canary itself, showing current line health and incident history. A marketing-page uptime percentage is a claim; a status page fed by around-the-clock real conversations with the production agents is evidence." } }, { "@type": "Question", "name": "Is automatic carrier failover on every plan?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. Canary monitoring, the public status page, owner alerting, and automatic carrier-level dead-man failover — the network-layer reroute that engages without human action — are included on every plan. Reliability isn't a tier; it's the product." } }, { "@type": "Question", "name": "What happens to emergencies while a line is in failover?", "acceptedAnswer": { "@type": "Answer", "text": "Calls ring the business's designated backup phone directly at the carrier, so a human answers them the old-fashioned way. The owner is alerted by email and SMS the moment failover engages and again when the line restores, and the whole episode is visible on the status page — nothing is silently absorbed." } }, { "@type": "Question", "name": "Do I need a separate backup number for failover to work?", "acceptedAnswer": { "@type": "Answer", "text": "No. The failover target is a phone you already own — the owner's cell, the on-call tech's phone, the shop line. You designate it once, and it only rings if failover engages. There's nothing new to buy, publish, or teach customers to dial; your business number stays the number." } }, { "@type": "Question", "name": "What if the phone carrier itself has an outage?", "acceptedAnswer": { "@type": "Answer", "text": "The carrier is the layer every phone number on earth trusts — a network-level outage affects your competitors' lines, your customers' cells, and every answering service equally, and no vendor honestly claims immunity to it. What architecture can control is everything above that layer, which is where nearly all real-world failures live: the AI model, the vendor's servers, the telephony provider. Those are the failures the canary catches and the carrier-level backstop routes around." } }, { "@type": "Question", "name": "How does this compare to a human answering service's reliability?", "acceptedAnswer": { "@type": "Answer", "text": "A staffed call center fails differently: its calls also ride software and telephony infrastructure, but its characteristic failure is capacity — hold queues and slow answers exactly when a storm has every contractor's phone ringing. An AI line answers instantly at any volume but depends on its stack being healthy, which is why the honest design assumes that stack can fail and puts the backstop below it. Whichever way you go, ask the same question: when your worst hour hits, what answers?" } }, { "@type": "Question", "name": "Can a line be switched to plain call forwarding on demand?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. The same carrier-forwarding mechanism the automatic failover uses can be engaged manually: an incident switchboard lets our operators flip any line — or every line — to forwarding in one action, and restore the AI just as fast. One request to support and it's done in moments, whether it's a planned event, a gut feeling, or a day you'd simply rather take calls directly." } } ] }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://callsaround.com" }, { "@type": "ListItem", "position": 2, "name": "Line Health & Reliability", "item": "https://callsaround.com/reliability" } ] } ] --- [CallsAround](/) [The 2 AM call](/anatomy-of-a-2am-call)[Pricing](/pricing)[Free line test](/free-line-test)[Status](/status)[Sign in](/login)[Get started](/signup) Line health & reliability # A phone line is infrastructure. We built it like infrastructure. CallsAround verifies every line is answerable by holding real conversations with it around the clock, and backstops the entire AI stack with plain carrier call forwarding at the phone network — a failover that works precisely when our servers don't. This page explains the architecture, layer by layer. ## How does CallsAround verify a line can actually answer? Most monitoring asks "is the server up?" — a question customers never ask. The question that matters is: _if a customer called this exact line right now, would the agent handle it?_ So that's the question we test. A conversational canary probes every line around the clock by holding a scripted conversation with the line's own production agent — through the same telephony path a real call takes — asking to reach a human and verifying the agent responds correctly, tool calls included. Because the probe exercises the full stack — telephony provider, AI model, our dispatch engine, and the line's specific configuration — it catches failure modes a health-check endpoint structurally cannot: a degraded model returning empty turns, a misconfigured agent, an upstream voice provider having a bad night. One failed probe is a data point; consecutive failures are an incident, and the system acts on its own. ## The layers, and what happens when each one fails A call passes through four layers. The design rule: every layer's failure is caught by a mechanism that lives _below_ it. Layer Failure mode What catches it AI voice model Empty turns, degraded responses, provider outage Canary conversations fail → consecutive-failure threshold → carrier failover CallsAround app & dispatch engine Server outage, bad deploy, database incident Canary can't complete → carrier failover engages at the network, which does not depend on our servers Telephony provider Call routing or media degradation Canary rides the same path and fails the same way → failover + alerting The carrier itself The phone network — the layer everything trusts This is where the backstop lives: plain call forwarding to the business's backup phone, the same mechanism every phone number on earth relies on ## Why is carrier-level failover different from an API-only architecture? Most AI answering products are built entirely _above_ the telephony API: the number lives at a VoIP provider, calls are handed to the vendor's application, and the application drives the AI. It's a fine architecture — until the application layer is the thing that fails. Then the call connects to silence, an error tone, or an infinite ring, because every mechanism that could have saved it lived in the layer that just went down. The vendor's own outage disables the vendor's own recovery. CallsAround puts the backstop one layer lower. When the canary detects repeated failures, the business number is switched to **plain carrier call forwarding at the phone network** — below our servers, below the AI, below the APIs. Callers ring the business's backup phone the way phone calls have been forwarded for decades. The failover's job is to work when nothing above it does, and it's the only place in the stack where that property can actually hold. Recovery is automatic and symmetric: probes keep running against the line, and when they pass again, forwarding switches off and the AI takes the line back — with the owner alerted at both transitions and the whole episode on the public record. ## Failing loudly: alerting and the public record Reliability isn't just staying up — it's never failing silently. Every transition is announced and journaled: - **Owner alerts** by email and SMS when failover engages and when the line restores. - **A public status page** at [callsaround.com/status](/status) driven by the canary itself — live health and incident history, not a static badge. - **An escalation journal** on every emergency call: who was rung, when, what answered, who accepted — timestamps, not memory. - **Uncovered-call alerts**: if an emergency exhausts the on-call chain, the whole team is told. An unanswered emergency is an incident, never a shrug. Canary monitoring, the status page, alerting, and automatic carrier-level failover cover every line on [every plan](/pricing). ## Reliability questions, answered straight ### Can callers ever reach dead air? ### What does the canary actually test? ### How fast is a failure detected and routed around? ### Do you publish an uptime number? ### Is automatic carrier failover on every plan? ### What happens to emergencies while a line is in failover? ### Do I need a separate backup number for failover to work? ### What if the phone carrier itself has an outage? ### How does this compare to a human answering service's reliability? ### Can a line be switched to plain call forwarding on demand? ## Verify us before you trust us with the line. Watch the status page, read how dispatch works, then put us on your overflow calls first — instant self-serve setup, month-to-month pricing. 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