From: [email protected] (Lars Poulsen) Subject: Re: 9xx Numbers (Ring-back, etc)
>>There are a series of 9xx number that can be dailed into any central >>office. One of these will result in a ring-back as soon as you hang >>up. Another will tell you the number (by recorded voice) of the line >>on which you are calling. (I have used this successfully from a New >>York City payphone by dialing 958.) Because it would be trivial to steal telephone service by patching into someone else's somewhat unused pair, if one could find out the number of such a pair that one might happen to patch into, the american local telephone companies have traditionally been very reluctant to make such information available to anyone other than authorized repair personnel. For me, who comes from a European background, this seemed very strange, until I learned that in American apartment buildings, it it quite common to run a group of pairs through an entire building, so that they appear behind a cover plate at many outlets in the building, rather than run pairs separately from each outlet location to a telephone panel at the service entrance to the building. In my GTE service area, the Automated Number Announcement is "114", easy to remember because it is the reverse of 411 (local directory information). In many places, the voice output of the equivalent service is fed to a loudspeaker in the switch room in order to let maintenance staff notice if it is being used unusually much. In the eastern US, it is apparently common to outfit xxx-9901 with a recording of the switch type and location. Apparently, in many western service areas, including my own, the xxx-99xx number range is now usually issued as customer directory numbers. Oldtimers remember how it was common to have unofficial conference bridges on numbers ending in xxx-991x. / Lars Poulsen
