Path: utzoo!attcan!uunet!lll-winken!ames!killer!vector!nobody From: johnl@ima.ISC.COM Newsgroups: comp.dcom.telecom Subject: Re: finding ringback numbers Message-ID: Date: 7 Jan 89 21:02:56 GMT Sender: chip@vector.UUCP Lines: 19 Approved: telecom-request@vector.uucp X-Originally-From: harvard!ima.ISC.COM!johnl (John R. Levine) X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 9, issue 7, message 5 In article Miguel_Cruz@ub.cc.umich.edu writes: >On most ESS systems, if you set up a reasonably intelligent modem to dial >each possible exchange followed by the last 4 digits of your phone number ... > >[Moderator's Note: The main thing that I do not like about this approach >is the ringing of *random telephones looking for something else.* ... Clearly the ringback prefix can't be the same as a valid exchange or you couldn't call anybody in that exchange. Program your modem to call only the unassigned prefixes to avoid pestering people. Most local phone books have a list of assigned prefixes in the local NPA. I also note that telcos often use a range of prefixes, e.g. in New Jersey they use 550 to 559 excepting 555. If you look at the assigned prefixes and see ten in a row that are unused, that's probably it. -- John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 492 3869 { bbn | spdcc | decvax | harvard | yale }!ima!johnl, Levine@YALE.something You're never too old to have a happy childhood.