Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!gryphon!vector!telecom-gateway From: kitty!larry@uunet.uu.net (Larry Lippman) Newsgroups: comp.dcom.telecom Subject: More on Digit-Absorbing Selectors Message-ID: Date: 14 Sep 89 02:51:24 GMT Sender: news@vector.Dallas.TX.US Lines: 32 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 372, message 2 of 5 > In article bmk@mvuxi.att.com (Bernard Mckeever) writes: > Larry and others mentioned dialing situations where the > digits would be absorbed over and over, I have seen this happen but it > was always a trouble, and resulted in wrong numbers or not enough > digits. Let me explain. The level 7 tandem office I worked in had 2nd > selectors set up to absorb digits 2,3,4, and 7. The switch would only > allow a digit [any digit] to be absorbed once. If the exchange you > were calling was 733 you could dial 743 and still get the right party. Most digit-absorbing selectors had a wiring option to absorb a given digit ONCE or REPEATEDLY, with the latter case allowing for an infinite number :-) of the same digit to be dialed. Sometimes in an office with two consecutive identical numbers (like 773) there was no choice but to set the 7-level for repeated absorption if the first selector was to be a combined local/toll/tandem selector. Therefore, the instance of repeated absorption was often not a case of trouble, but was simply a quirk of the particular office switching layout and the particular digit-absorbing selectors. Some digit-absorbing selectors were more complex than others. A full-featured digit-absorbing selector (like the SD-30976) was sophisticated (I use this term loosely :-) ) enough to decide on a level by level basis whether to absorb once, absorb repeatedly, rotate to ATB, select a path to a second selector or select a path to an outgoing trunk. The above was a pretty common digit-absorbing selector and was used on No. 1, 350A, 355A, 356A and 360A SxS apparatus. I remember it "fondly". :-) <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {allegra|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> TEL 716/688-1231 | 716/773-1700 {hplabs|utzoo|uunet}!/ \uniquex!larry <> FAX 716/741-9635 | 716/773-2488 "Have you hugged your cat today?"