ASR is a ratio, not a grade
Answer-Seizure Ratio is answered calls divided by attempted calls. It rises with good destinations, clean CLI and reasonable dialling behaviour, and falls with aggressive retries, bad lists and blocked ranges. A route quoted at a single ASR figure for a whole country is being summarised, not described — ask for the per-prefix breakdown and the window it was measured over.
- Ask which destinations and prefixes the figure covers
- Ask over what period and volume it was measured
- Compare it against your own traffic profile, not the seller's
ACD tells you what kind of calls survive
Average Call Duration exposes what ASR hides. A high ASR with a very low ACD usually means calls connect and die — false answer supervision, early media treated as an answer, or a media path that breaks after connect. For most legitimate traffic a healthy ACD is the strongest single indicator that a route is real.
CLI, white and grey are commercial descriptions
There is no universal registry behind these words, so treat them as claims to verify. CLI routes are expected to pass your caller ID intact to the terminating network. White routes are expected to be carrier-terminated and interconnect-legal end to end. Grey routes are everything else, and in many jurisdictions they carry real legal exposure for whoever originates the traffic. Ask the seller to state the termination path in writing in the order chat.
- Does my CLI arrive unmodified, and on which destinations?
- Is termination direct or through how many hops?
- What is the policy on CLI overwriting when a destination rejects it?
Test before you commit volume
A test window is worth more than any quoted metric. Send your own traffic, at your own pace, to your own destination mix, and read your own CDRs. Keep the test inside the platform's inspection window so the evidence you collect is still usable if you need to dispute.
- Test the destinations you will actually dial, in your real ratios
- Watch post-dial delay and one-way audio, not only connect rates
- Record the codec and whether transcoding happens mid-path
- Save your CDR summary into the order chat before confirming delivery
Takeaways
- ASR without destination, window and traffic type is marketing
- Low ACD next to high ASR is the classic false-answer signature
- CLI, white and grey are claims — get the termination path in writing
- Your own test traffic beats any quoted figure