Path: utzoo!attcan!utgpu!watmath!clyde!att!osu-cis!killer!vector!nobody From: westmark!dave@rutgers.edu (Dave Levenson) Newsgroups: comp.dcom.telecom Subject: CLASS(sm) Service Message-ID: Date: 7 Jan 89 22:26:24 GMT Sender: chip@vector.UUCP Lines: 24 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 9, issue 10, message 1 New Jersey Bell has begun offering ISDN-based custom-calling services, under the service mark CLASS. One of these is called Caller*ID service. It displays the calling number while your phone is ringing. To use it, you buy (from the telephone company, or from others) a device that is bridged on to your standard tip/ring line and has a display on it. Does anybody know the signalling method between the CO and the caller-id display box? I have determined that it is in-band analog, and sounds like a modem. After the first ring, there is a burst of carrier, then some modulation, then more carrier, and then the next ring. The data-burst occurs only once, after the first ring, for each incoming call. The modulation technique and data format are probably public information, as you can (theoretically) buy the display box from anybody. But where is the information available? Bellcore... are you listening? -- Dave Levenson Westmark, Inc. The Man in the Mooney Warren, NJ USA {rutgers | att}!westmark!dave