Every monitor needs a rule for what "working" means. That rule is the Success Criteria you pick when you create or edit a test. Choose it to match how the line actually behaves when it is healthy — a rule that is stricter than the line can satisfy will report failures forever.
The options
| Success Criteria | The test passes when | Best for |
|---|---|---|
| Answer Only | The call is answered | Lines that just have to pick up: courtesy phones, backup lines, a number you rarely dial |
| Answer + Any DTMF | Answered, and the far end sends any touch-tone digits | Panels and boxes that always send a tone once connected |
| Answer + Specific DTMF | Answered, and the digits exactly match what you entered | Equipment with a known confirmation code |
| Answer, No Voicemail | Answered by something that is not a voicemail greeting | Lines that must reach a person, where a diverted call is a failure |
Answer Only
The simplest and the right default. If the line rings and something picks up, the test passes. Use it unless you have a specific reason not to.
Touch-tone checks
Some emergency phones and alarm panels send a tone when they connect. If yours does, a touch-tone check is stronger than answer alone, because it proves the equipment on the other end is alive rather than just the line.
- Answer + Any DTMF — any digits at all satisfy the check.
- Answer + Specific DTMF — you enter the exact sequence in Required DTMF Input. Only digits,
*,#, andA–Dare accepted, up to 20 characters.
If you pick Answer + Specific DTMF and leave the digits blank, the test cannot pass. The portal will not let you save it empty — but if you clear the field later, every run afterwards fails.
Test this one manually first. Run it once, open the result, and look at DTMF Received to see exactly what the line sends. Then set your required sequence to match.
Voicemail
Treat voicemail as failure is switched on by default and works alongside whichever criteria you choose. A line that has quietly been forwarded to a voicemail box is a broken line for monitoring purposes, so we count it as a failure. Switch this off only for lines where reaching voicemail is genuinely acceptable.
Answer, No Voicemail makes that the whole rule: the line must be answered by something other than a voicemail greeting.
Changing your mind
Success criteria can be changed at any time from Line Verification → Monitors → Configure Tests, then Edit. The change applies to future runs; past results keep the rule they ran under.
What is not available yet
Audio quality checking — passing or failing a line on measured call quality such as MOS score, jitter, or packet loss — is not available. You may see quality fields on the History screen; they are not populated, and a monitor set to check quality will report a failure on every run even when the line is perfectly healthy. Use one of the four criteria above instead. We will update this article when quality checking ships.