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AMDSure vs SignalWire Answering Machine Detection
SignalWire, the company behind FreeSWITCH, charges a flat per-call fee for AMD on calls placed through its cloud.
| AMDSure | SignalWire AMD | |
|---|---|---|
| The 3% abandon rule | Shadow mode measures people wrongly sent to voicemail on your own calls, beside your built-in AMD(), with the sample size: your detector's share of the 3% abandon rate, before you switch. People are decided first, 2.55 s on average. | No published error rates. Only on SignalWire calls. |
| How it decides | A compiled agent on your Asterisk box measures the call (a real voice detector, tones, a learned acoustic model, the sound of the pickup itself); AMDSure's server applies the rules and signs the verdict. | SignalWire's engine on its own media. |
| Where the audio goes | Stays on your server. The agent sends numbers (speech probabilities, tone events, model scores), never audio, unless you switch learning on. | The call is already on SignalWire. |
| Time to a verdict | Median 4.6 s to a verdict on live calls from the pickup, 2.3 s on recordings that start mid-greeting; short greetings decide at about 2 s, beeps and known greetings sooner. | Not published. |
| Price | Free: 50,000 verdicts a month, two servers, no card. Starter $69 a month for 500,000 then $0.0002; Growth $269 for 5,000,000 then $0.00012; Scale $899 for 25,000,000 then $0.00008. | $0.006 per call (SignalWire voice pricing). |
| What it reports | Person, voicemail, call screener, unsure, each with a reason, a confidence and the time to the verdict. And what answered, by name: Verizon, AT&T and other carriers' default greetings, number read-outs, iPhone, Samsung and Google call screening, a disconnected number (the intercept tones), fax, busy, dead air, a false answer. Stamped on the call as AMDSURE_KIND for the dialer. | Human or machine, with an optional wait for the beep. |
| Works on | Asterisk 18 to 22 and everything built on it: VICIdial, ViciBox, FreePBX, Issabel, GoAutoDial, custom dialers. FreeSWITCH in development. | SignalWire voice API only. |
| Proof before you switch | Shadow mode runs beside your built-in AMD() on every call and stamps its verdict on the call; the dashboard shows people wrongly sent to voicemail and voicemails caught, against AMD(), before you switch. | None published. |
| When it fails | Open, to your own AMD(). A brain outage costs seconds, never a call. | Not published. |
| Your audio and training | Your call audio is used for training only with the learning checkbox on, which you can turn off at any time; phone numbers are never seen. | Per SignalWire's terms. |
Where SignalWire AMD is good
Built into SignalWire's voice API. Per call.
- One flag on a SignalWire call.
Where AMDSure differs
- AMDSure works on any Asterisk dialer and any carrier.
- 500,000 answered calls a month are $3,000 on SignalWire against $69 on AMDSure Starter.
Sources
Facts about SignalWire AMD come from its own documentation and pricing pages on the dates noted; tell us at [email protected] if something has changed and we will fix it. Other comparisons: Stock AMD(), FreeSWITCH AMD, AMDY, Twilio AMD, Telnyx AMD, Plivo, Vonage, VM Hunter.
See it on your own traffic.
A 20 minute call. We show the console with live numbers, then set up shadow mode on your dialer so you can judge for yourself.
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