slr@tybalt.caltech.edu (Steve Rhoades) (10/26/90)
This question is primarily targeted for those of you with Caller*ID. Since the FSK Caller*ID data is sent between the first and second rings, I was wondering if it's possible to actually hear it using a butt set in the monitor position. Or for that matter, any kind of monitor that wouldn't produce and "off hook" condition. On a related note, can someone point me to the specs on demodulating this data ? It's probably in a BSTJ somewhere. (remember BSTJs ?) Steve slr@tybalt.caltech.edu
dave@westmark.westmark.com (Dave Levenson) (10/27/90)
In article <14044@accuvax.nwu.edu>, slr@tybalt.caltech.edu (Steve Rhoades) writes: > This question is primarily targeted for those of you with Caller*ID. > Since the FSK Caller*ID data is sent between the first and second > rings, I was wondering if it's possible to actually hear it using a > butt set in the monitor position. Or for that matter, any kind of > monitor that wouldn't produce and "off hook" condition. Yes. Caller*ID, when monitored with a butt-set in on-hook monitor mode, sounds like a simplex FSK modem (remember the old 202 dataset?) between the first and second ring. When NJ Bell shut off the feature on one of our lines by mistake, I told their craftsperson (who called and told me that my display unit was at fault) that I was unable to hear the 'modem-like tone' after the first ring with a butt-set. He tried it. He then believed me. The service was restored within the hour. > On a related note, can someone point me to the specs on demodulating > this data ? It's probably in a BSTJ somewhere. (remember BSTJs ?) Bellcore Technical Reference TR-TSY-000030: "SPCS Customer Premises Equipment Data Interface" This describes the modulation, bit rate, signal levels, and the rest of the 'physical layer' of the interface. Bellcore Technical Reference TR-TSY-000031: "CLASS Feature: Calling Number Delivery" This describes the message format, coding, and in general, the application and presentation layers of the interface. These and other Bellcore documents may be ordered by calling (908) 699-5802. (Have a credit card ready!) Dave Levenson Internet: dave@westmark.com Westmark, Inc. UUCP: {uunet | rutgers | att}!westmark!dave Warren, NJ, USA AT&T Mail: !westmark!dave [The Man in the Mooney] Voice: 908 647 0900 Fax: 908 647 6857