VoIP glossary · Answer-Seizure Ratio
What is ASR?
ASR (Answer-Seizure Ratio) is the percentage of call attempts on a route that are answered, calculated as answered calls divided by total attempts.
ASR explained
A "seizure" is any attempt the carrier accepts and tries to complete. ASR therefore includes calls that fail for reasons outside the network, such as busy lines, unanswered phones and wrong numbers. That is why ASR is never close to 100% even on a perfect route.
ASR is most useful as a trend. A route that normally answers 45% of attempts and suddenly drops to 20% is telling you something changed, whether that is a downstream carrier problem, a blocked caller ID, or a dialler pushing poor-quality lists. Always look at ASR alongside ACD, because a route can show a high ASR with very short calls if answer supervision is wrong.
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