A blocklist (formerly often called a blacklist) is a security pattern that uses a default-allow approach for known bad actors: you explicitly deny specific sources, while everyone else is permitted unless another control (such as an allowlist) says otherwise. Blocklists are a practical way to stop repeat spam, harassment, or known-abusive callers without locking down your entire hotline.
Blocklist vs. blacklist
Blacklisting was the traditional term for denying specific IPs, domains, or phone numbers. Modern documentation and products, including All Quiet, use blocklist for the same mechanism. If you see "blacklist" in older runbooks or firewall UIs, it means the same thing as blocklist here.
Key benefits of blocklisting
- Stops known nuisance callers: Block repeat wrong numbers, robocall sources, or internal test lines without changing on-call schedules.
- Regional or prefix controls: Block entire country prefixes (e.g. +44) when a number should only serve a specific geography.
- Complements allowlists: Use a blocklist for known bad entries and an allowlist when you need strict "only these callers" mode.
Blocklisting in Live Call Routing
In Live Call Routing, the blocklist is configured under Call Routing → Caller allow & block lists. Any caller whose number matches a blocklist entry, whether an exact number or prefix, is rejected on the first inbound webhook. The call never reaches your welcome message, keypad menu, or on-call escalation path.
Rejected calls appear in Call Logs with outcome Blocklisted. The detailed log shows a single step, CallerBlocklisted: the call hung up immediately, no voicemail was recorded, and no incident was created. You can filter the session list by outcome Blocklisted to audit rejected traffic.
How blocklist and allowlist interact
When both lists are configured, blocklist is evaluated first. A caller on the blocklist is always rejected, even if they would otherwise match the allowlist. If only a blocklist is set (allowlist empty), all callers are permitted except those blocked. If only an allowlist is set, callers who do not match are also rejected and logged as Blocklisted, even though they were blocked by the allowlist rather than the blocklist.
Blocklisting vs. IP controls in monitoring
Live Call Routing blocklists apply to caller phone numbers, not to All Quiet's monitoring probes. For API and website monitoring, the related concept on your side is often a firewall deny list or WAF rule that blocks unwanted inbound traffic. All Quiet's HTTP and Ping monitors instead ask you to allowlist our outbound IPs so probes are explicitly permitted. Blocklist and allowlist are two sides of the same access-control coin: blocklist says "never these," allowlist says "only these."
The All Quiet bridge
All Quiet's Live Call Routing blocklist gives you provider-agnostic caller filtering inside the product, with no Twilio Studio flow required for basic number blocking. Pair it with an allowlist when you need a locked-down hotline for VIP or internal callers only, and use call logging to verify that unwanted numbers are being stopped before they wake your on-call team.
