The answer-seizure ratio (ASR) is a measurement of network quality and call success rates. It is the percentage of answered telephone calls with respect to the total call volume. The answer-seizure ratio is defined as 100 times the ratio of answered calls, i.e. the number of seizures resulting in an answer, divided by the total number of seizures.
An answered call is defined as an established SIP Dialog with a 200 OK final response.
A seizure is defined as an established SIP Dialog with a final response (2xx,3xx,4xx,5xx,6xx).