5 ms·

What kind of testing (and from whom) would have caught this?

by nikanj 5y ago

deleted 5y ago
[deleted]
isbvhodnvemrwvn 5y ago
Google should have built in some mechanism which verifies that the integration from Teams can't prevent calling 911 - either as part of Play Store verification, or as a general test of their system (they delegate to other apps, if these fail or hang the native mechanism should take over).
- midjji 5y ago
  Or just generally make it impossible to interfere with the calling process. There is zero need for it after all.
  - rjmunro 5y ago
    Having something that can screen calls for spam, something that can stop you accidentally dialling a premium rate number and getting an unexpected large bill, or something that can intercept a call and route it over a cheaper VoiP connection is really useful. It needs to be a carefully managed feature, but it's certainly not "zero need".
    - megous 5y ago
      Adn that's ok. 911/112/etc. calls should just not be screenable or blockable by apps or susceptible to third party app crashes. They should be short-circuited to just happen on the default phone app, with little possibility for any interference from apps on the system.
deleted 5y ago
[deleted]
michaelt 5y ago
If you have a design where you cannot test 911 functionality, or where you can test it, but that testing is not sufficient to ensure the functionality works then your design is not fit for purpose.
deleted 5y ago
[deleted]
myself248 5y ago
At least in vehicle infotainment systems, we test 911 functionality EXTENSIVELY. It's a major part of call testing, because dialing 911 overrides all sorts of lockouts and exercises code paths that aren't otherwise well-covered by testing. Usually there's a hidden config register where we can change "the number for 911", so for some portion of testing, we'll set that to "Chris's phone" and inundate a coworker with calls, but once we've been through a shakedown with that, it's time to coordinate with the local PSAP and identify a slow time when they can field some real test calls from us. There are all sorts of safeguards here -- they want a regular phone number for one of the testers, so if the test phone malfunctions in any way (say, calls complete but audio doesn't open), they can reach us out-of-band. And it's always perfectly clear that they can cancel the activity at any time, if enough real 911 calls come in that they don't have spare operators for our testing. It's been a long time since I was on the carrier side, but I remember doing tower turn-ups, we'd also place one test call per carrier-sector, to make sure the location info was transferred correctly. Similar coordination but it was largely a formality because it was usually just 3 or 6 calls, and very brief ones at that. In the instant case, both the phone maker (Google) and the carrier (unsure) should've exercised this in their acceptance testing. Since it sounds like a Teams bug, it's understandable that they didn't catch it, but also unacceptable that Teams could interfere with the ability to dial 911. Since we've now learned that apps can interfere with that, this hugely balloons testing requirements until/unless they fix the OS so apps cannot interfere.
- OldHand2018 5y ago
  > At least in vehicle infotainment systems, we test 911 functionality EXTENSIVELY. It's a major part of call testing, because dialing 911 overrides all sorts of lockouts and exercises code paths that aren't otherwise well-covered by testing. When I worked at Motorola doing mobile infrastructure, you couldn't even merge your code into a release candidate branch unless it was tested against emergency calls, for all the reasons you listed (plus more). We used giant attenuators screwed on to the antenna plugs because everything had to be running at full power to ensure that it was as life-like as possible. Every once in a while, though, someone didn't screw the attenuator on tight enough and the emergency call would be picked up on the real mobile network and the fire department would show up in our parking lot.

What kind of testing (and from whom) would have caught this?

by nikanj 5y ago

What kind of testing (and from whom) would have caught this?

deleted 5y ago

[deleted]

isbvhodnvemrwvn 5y ago

Google should have built in some mechanism which verifies that the integration from Teams can't prevent calling 911 - either as part of Play Store verification, or as a general test of their system (they delegate to other apps, if these fail or hang the native mechanism should take over).

midjji 5y ago
Or just generally make it impossible to interfere with the calling process. There is zero need for it after all.
- rjmunro 5y ago
  Having something that can screen calls for spam, something that can stop you accidentally dialling a premium rate number and getting an unexpected large bill, or something that can intercept a call and route it over a cheaper VoiP connection is really useful. It needs to be a carefully managed feature, but it's certainly not "zero need".
  - megous 5y ago
    Adn that's ok. 911/112/etc. calls should just not be screenable or blockable by apps or susceptible to third party app crashes. They should be short-circuited to just happen on the default phone app, with little possibility for any interference from apps on the system.

deleted 5y ago

[deleted]

michaelt 5y ago

If you have a design where you cannot test 911 functionality, or where you can test it, but that testing is not sufficient to ensure the functionality works then your design is not fit for purpose.

deleted 5y ago

[deleted]

myself248 5y ago

At least in vehicle infotainment systems, we test 911 functionality EXTENSIVELY. It's a major part of call testing, because dialing 911 overrides all sorts of lockouts and exercises code paths that aren't otherwise well-covered by testing. Usually there's a hidden config register where we can change "the number for 911", so for some portion of testing, we'll set that to "Chris's phone" and inundate a coworker with calls, but once we've been through a shakedown with that, it's time to coordinate with the local PSAP and identify a slow time when they can field some real test calls from us. There are all sorts of safeguards here -- they want a regular phone number for one of the testers, so if the test phone malfunctions in any way (say, calls complete but audio doesn't open), they can reach us out-of-band. And it's always perfectly clear that they can cancel the activity at any time, if enough real 911 calls come in that they don't have spare operators for our testing. It's been a long time since I was on the carrier side, but I remember doing tower turn-ups, we'd also place one test call per carrier-sector, to make sure the location info was transferred correctly. Similar coordination but it was largely a formality because it was usually just 3 or 6 calls, and very brief ones at that. In the instant case, both the phone maker (Google) and the carrier (unsure) should've exercised this in their acceptance testing. Since it sounds like a Teams bug, it's understandable that they didn't catch it, but also unacceptable that Teams could interfere with the ability to dial 911. Since we've now learned that apps can interfere with that, this hugely balloons testing requirements until/unless they fix the OS so apps cannot interfere.

OldHand2018 5y ago
> At least in vehicle infotainment systems, we test 911 functionality EXTENSIVELY. It's a major part of call testing, because dialing 911 overrides all sorts of lockouts and exercises code paths that aren't otherwise well-covered by testing. When I worked at Motorola doing mobile infrastructure, you couldn't even merge your code into a release candidate branch unless it was tested against emergency calls, for all the reasons you listed (plus more). We used giant attenuators screwed on to the antenna plugs because everything had to be running at full power to ensure that it was as life-like as possible. Every once in a while, though, someone didn't screw the attenuator on tight enough and the emergency call would be picked up on the real mobile network and the fire department would show up in our parking lot.