From the linked FAQ:
How can I make a test 9-1-1 call?
To make a test 9-1-1 call, you need to first contact the 9-1-1 center that serves your area. The non-emergency numbers for Colorado's 9-1-1 centers are available here(opens in new window). If you're unsure which 9-1-1 center serves your area, call the 911 Program at 303-894-2871, and we'll help you identify the 9-1-1 center for the location you want to test from.
When you call the 9-1-1 center, ask them if it would be okay to make a test 9-1-1 call. If they are particularly busy or are handling a major incident, they may ask you to call back at a later time.
When your phone cannot make normal calls for whatever reason¹, you obviously want to know if 911 calls will at least work. And the idiots design a test procedure that requires normal phone calls to work.
① Typical reasons why you may be unable to make normal calls:
- You have a GSM phone with no GSM chip, or unsubscribed chip.
- You are on a prepaid plan and have no credit.
So indeed the telecom industry has a glaring competency problem.
A test number would suffice in some situations. When an incompetent VOIP provider takes an action to block calls “for security purposes”, they cannot legally block /all/ calls. 911 calls must be permitted. I do not trust their competency. And 911 test calls would obviously require the same status. If their call blocking allows a 911 test number through, it proves that their blockade is not a simple crude block on /everything/.
A test number would not be the only solution. With some services you can set the CID to whatever you want. So in principle a CID of 555-1212 could have special meaning to 911 receiptionists. So a tester would set the CID info to that number before calling 911.
911 is not always instantly answered by humans. When answered by a machine, there could be a cancel code. E.g. dial “119” after connecting to cancel it.
Sure, if you need that extra level of certainty.