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The Telecom Digest for November 22, 2010
Volume 29 : Issue 315 : "text" Format

Messages in this Issue:

On preliminary false switchhook pulsing(Lisa or Jeff)
Paging alackrity@comcast.net [nfp](Telecom Digest Moderator)

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Date: Sun, 21 Nov 2010 10:18:40 -0800 (PST) From: Lisa or Jeff <hancock4@bbs.cpcn.com> To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org. Subject: On preliminary false switchhook pulsing Message-ID: <84bc095d-5837-4ada-b854-d9f50bcc8593@l32g2000yqc.googlegroups.com> I checked the Bell Labs history ("Switching, 1925-1975") to see what was said preliminary false switchhook pulsing. There wasn't much, and I couldn't find anything in the 1875-1925 book. For SxS offices: "arrangements were developed to prevent wrong numbers due to preliminary pulses which might be falsely generated at the start of a call when the receiver is first taken off hook. This also resulted in the standardization of 11X service codes compared with X11 for the panel system. Ref: "Counteracting Dialing Errors in the Step by Step System", Bell Labs Record, January 1929, p 198. Implementing DDD: To add long distance to an SxS office on the basis of area code (0/1) would've been expensive due to adding senders/registers or building out the switch train. The easier way was to add 1 as a prefix. "An exception was the elimination of preliminary pulse detection, a feature that was abandoned with the obsolescence of the desk stand telephone." * * * * I am not sure why panel switching didn't have the problem that SxS since both systems in their early days used desk-stand (candlestick) phones. Unfortunately, I don't have easy access to library issues of Bell Labs Record to study this further. I hope someday they put the record on line; it would answer many historical questions.
Date: Sun, 21 Nov 2010 14:49:34 -0500 From: Telecom Digest Moderator <redacted@invalid.telecom.csail.mit.edu> To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org. Subject: Paging alackrity@comcast.net [nfp] Message-ID: <20101121194934.GA24589@telecom.csail.mit.edu> Paging alackrity@comcast.net: please contact me off-list. If you prefer, my phone number is +1-339-364-8487. Bill -- Bill Horne Moderator
TELECOM Digest is an electronic journal devoted mostly to telecom- munications topics. It is circulated anywhere there is email, in addition to Usenet, where it appears as the moderated newsgroup 'comp.dcom.telecom'. TELECOM Digest is a not-for-profit, mostly non-commercial educational service offered to the Internet by Bill Horne. All the contents of the Digest are compilation-copyrighted. You may reprint articles in some other media on an occasional basis, but please attribute my work and that of the original author. The Telecom Digest is moderated by Bill Horne. Contact information: Bill Horne Telecom Digest 43 Deerfield Road Sharon MA 02067-2301 781-784-7287 bill at horne dot net Subscribe: telecom-request@telecom-digest.org?body=subscribe telecom Unsubscribe: telecom-request@telecom-digest.org?body=unsubscribe telecom This Digest is the oldest continuing e-journal about telecomm- unications on the Internet, having been founded in August, 1981 and published continuously since then. Our archives are available for your review/research. We believe we are the oldest e-zine/mailing list on the internet in any category! URL information: http://telecom-digest.org Copyright (C) 2009 TELECOM Digest. All rights reserved. Our attorney is Bill Levant, of Blue Bell, PA. --------------------------------------------------------------- Finally, the Digest is funded by gifts from generous readers such as yourself who provide funding in amounts deemed appropriate. Your help is important and appreciated. A suggested donation of fifty dollars per year per reader is considered appropriate. See our address above. Please make at least a single donation to cover the cost of processing your name to the mailing list. All opinions expressed herein are deemed to be those of the author. Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization.
End of The Telecom Digest (2 messages)

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