5 ms·

what they are doing is initiating a call far enough for the phone system to busy out your phone, then very quickly placing a second call that the phone system s

what they are doing is initiating a call far enough for the phone system to busy out your phone, then very quickly placing a second call that the phone system sends straight to voicemail as your phone is busy. I can tell you that's exactly what they are doing.

smacktoward 9y ago
This is fascinating. It never occurred to me until now that there might be a window in the call process between "line is flagged as busy" and "phone rings." I assume we're talking about a very narrow window here, right? How narrow? Is it something that has always existed, or something that crept in because of the transition from phone-as-mechanical-device to phone-as-software?
- tormeh 9y ago
  Could be a second or two. The traditional phone systems are dog slow. Often takes 15 secs from A starts ringing to B does.
  - spc476 9y ago
    I can confirm. At work I have to deal with call processing [1], and the time guard [2] is 15 seconds on the originating side [3] for CDMA [4]. [1] We provide enhanced caller ID---a name in addition to the phone number. Our new product will also mark known telemarketers. [2] The amount of time we have to do what we do [3] The calling party---the one initiating the phone call. [4] which may be enough to identify the carrier we work with.
- semi-extrinsic 9y ago
  As long as it's a fairly consistently timed window (and I assume it is), it doesn't matter if it's just a few milliseconds. On a related note, I'm still surprised to find that telephone operators haven't fixed the scenario "someone calls me and I just miss it, I call them back while they're trying to call me for the second time, and we both get a busy signal". As a naive outsider, seems like it wouldn't take much to just connect those two calls.
  - Sir_Substance 9y ago
    >As a naive outsider, seems like it wouldn't take much to just connect those two calls. Who would you charge for the call?
    - kaslai 9y ago
      All phones services I've used charge for total usage, regardless of the initiator. If someone calls me, I still get dinged for every minute I'm on the line, same as if I placed an outgoing call. (Granted, I've only used pay-as-you-go type services, so perhaps other services are different.)
      - josteink 9y ago
        In Europe all services I have seen has been of the kind where whoever makes the call pays, and nobody ever gets charged for receiving calls. Under such a system, this can become a issue.
        Moru 9y ago
        I bet from the phone company they don't see the problem. Both were intending to place a call so they both pay :)
      - threeseed 9y ago
        Apparently only the US and Canada charge the phone owner for incoming calls. https://en.wikipedia.org/wiki/GSM_services#Incoming_calls https://en.wikipedia.org/wiki/GSM_services#Incoming_calls Europe, Asia, Australia etc all charge the caller.
        kalleboo 9y ago
        This leads to awkward situations like when I called someone in the US and they were worried that they're going to get charged international rates for a call from abroad.
        9y ago
- pbhjpbhj 9y ago
  I hear the crackling of my PC speakers a few seconds before the call rings on my mobile; similarly on our landline the phone lights up and shows the caller ID a second or so before it rings. Also if you ring a phone in the same room as you [we have kids!] you'll often find you get a ring tone long before the callee's phone rings.
  - SyneRyder 9y ago
    > on our landline the phone lights up and shows the caller ID a second or so before it rings Not sure about the US, but in Australia this is a phone specific feature. The Caller ID comes between the first and second ring, so if you want a call blocking feature that is completely silent, you need to silence the first ring of every call. Some phones will do this automatically, others (like my Panasonic landline) make it an option you can turn on & off. The Panasonic FAQ has some info: http://eng.faq.panasonic.com/app/answers/detail/a_id/26547/~/i-want-to-block-calls-on-my-phone.-can-my-phone-do-this%3F-kx-tge-series%2C http://eng.faq.panasonic.com/app/answers/detail/a_id/26547/~...
    - pbhjpbhj 9y ago
      I'm in UK, cheap German portable landline phone with virtually no useful settings. Could well be phone specific as you suggest.

smacktoward 9y ago

This is fascinating. It never occurred to me until now that there might be a window in the call process between "line is flagged as busy" and "phone rings." I assume we're talking about a very narrow window here, right? How narrow? Is it something that has always existed, or something that crept in because of the transition from phone-as-mechanical-device to phone-as-software?

tormeh 9y ago
Could be a second or two. The traditional phone systems are dog slow. Often takes 15 secs from A starts ringing to B does.
- spc476 9y ago
  I can confirm. At work I have to deal with call processing [1], and the time guard [2] is 15 seconds on the originating side [3] for CDMA [4]. [1] We provide enhanced caller ID---a name in addition to the phone number. Our new product will also mark known telemarketers. [2] The amount of time we have to do what we do [3] The calling party---the one initiating the phone call. [4] which may be enough to identify the carrier we work with.
semi-extrinsic 9y ago
As long as it's a fairly consistently timed window (and I assume it is), it doesn't matter if it's just a few milliseconds. On a related note, I'm still surprised to find that telephone operators haven't fixed the scenario "someone calls me and I just miss it, I call them back while they're trying to call me for the second time, and we both get a busy signal". As a naive outsider, seems like it wouldn't take much to just connect those two calls.
- Sir_Substance 9y ago
  >As a naive outsider, seems like it wouldn't take much to just connect those two calls. Who would you charge for the call?
  - kaslai 9y ago
    All phones services I've used charge for total usage, regardless of the initiator. If someone calls me, I still get dinged for every minute I'm on the line, same as if I placed an outgoing call. (Granted, I've only used pay-as-you-go type services, so perhaps other services are different.)
    - josteink 9y ago
      In Europe all services I have seen has been of the kind where whoever makes the call pays, and nobody ever gets charged for receiving calls. Under such a system, this can become a issue.
      - Moru 9y ago
        I bet from the phone company they don't see the problem. Both were intending to place a call so they both pay :)
    - threeseed 9y ago
      Apparently only the US and Canada charge the phone owner for incoming calls. https://en.wikipedia.org/wiki/GSM_services#Incoming_calls https://en.wikipedia.org/wiki/GSM_services#Incoming_calls Europe, Asia, Australia etc all charge the caller.
      - kalleboo 9y ago
        This leads to awkward situations like when I called someone in the US and they were worried that they're going to get charged international rates for a call from abroad.
      - 9y ago
pbhjpbhj 9y ago
I hear the crackling of my PC speakers a few seconds before the call rings on my mobile; similarly on our landline the phone lights up and shows the caller ID a second or so before it rings. Also if you ring a phone in the same room as you [we have kids!] you'll often find you get a ring tone long before the callee's phone rings.
- SyneRyder 9y ago
  > on our landline the phone lights up and shows the caller ID a second or so before it rings Not sure about the US, but in Australia this is a phone specific feature. The Caller ID comes between the first and second ring, so if you want a call blocking feature that is completely silent, you need to silence the first ring of every call. Some phones will do this automatically, others (like my Panasonic landline) make it an option you can turn on & off. The Panasonic FAQ has some info: http://eng.faq.panasonic.com/app/answers/detail/a_id/26547/~/i-want-to-block-calls-on-my-phone.-can-my-phone-do-this%3F-kx-tge-series%2C http://eng.faq.panasonic.com/app/answers/detail/a_id/26547/~...
  - pbhjpbhj 9y ago
    I'm in UK, cheap German portable landline phone with virtually no useful settings. Could well be phone specific as you suggest.