Every wholesale conversation eventually reaches the same two abbreviations. They are worth understanding properly, because they are how you tell a route that is failing you from a calling list that is.
ASR: of the calls you tried, how many were answered
Answer-seizure ratio is answered calls divided by attempted calls. Make 1,000 attempts, have 420 answered, and the ASR is 42%.
“Seizure” is old telephone language for an attempt that took hold of a line. In a VoIP world, read it as every call you sent to the route, whatever happened next.
ACD: how long the answered calls lasted
Average call duration is total answered minutes divided by the number of answered calls. 420 answered calls adding up to 1,260 minutes gives an ACD of 3 minutes.
ASR tells you whether calls connect. ACD tells you whether, once connected, people stayed on. A route can be good at one and bad at the other, and the combination is where the diagnosis lives.
There is no single “good” number
The most common mistake is comparing an ASR with somebody else’s. ASR depends more on your traffic than on the route:
- Calls people expect — customers ringing a business, or a business returning a call — are mostly answered, so ASR runs high.
- Outbound sales to a cold list runs far lower, because people let unknown numbers ring, and a share of any list is disconnected or out of date. An ASR in the twenties or thirties can be entirely normal there.
- Destination and time move it too: mobiles and landlines behave differently, and so does 10am against 6pm.
So compare like with like. The same list, at the same time of day, split across two routes — whatever difference remains is the route.
NER: separating the network from the people
ASR counts a busy line or an unanswered phone as a failure, though the network did nothing wrong. Network effectiveness ratio counts those as successes — the network delivered the call and a person chose not to take it — and counts only the calls the network itself failed.
A low ASR with a healthy NER points at your list. A low NER points at the route. Ask a provider for both.
Patterns that point at the route
- ASR falls suddenly with nothing else changed. Same list, same hours, fewer answers. Look at the SIP responses behind the failures — a rise in 503, 480 or 408 is the route, and this guide explains what each one means.
- ASR is normal but ACD is short. Calls connect and then people hang up quickly. That is often audio: one-way speech, choppiness or delay. There is a diagnosis guide here.
- A cluster of answered calls lasting almost exactly the same few seconds. This is the signature of false answer supervision, where a route signals that a call was answered before anyone picked up, so ringing or an announcement gets billed. Listen to a handful of recordings; ringing on a call your CDR says was answered settles it.
- Long post-dial delay. Callers hear silence for several seconds before ringing and hang up first. It drags ASR down and makes agents think the dialler is broken.
Reading your own CDRs
- Group calls by route, by destination type, and by hour of day.
- Work out ASR and ACD for each group.
- Add one more figure: the share of answered calls under six seconds. It is the quickest early warning of both audio problems and false answers.
- Track all three daily, and look at the trend rather than any single day.
A cheap route with a poor ASR costs more than it looksEvery failed attempt is agent time spent waiting for nothing. A route a fraction of a penny cheaper per minute can be the expensive one once you count what your team did while it failed — the same argument as least cost routing.
Direct Tier-1 routes, judged on ASR and ACD as well as price.
See our UK routes
