Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!sdd.hp.com!spool.mu.edu!telecom-request From: kitty!larry@uunet.uu.net (Larry Lippman) Newsgroups: comp.dcom.telecom Subject: Re: 9's in Telephone Numbers Message-ID: Date: 22 May 91 04:31:06 GMT Sender: Telecom@eecs.nwu.edu Organization: TELECOM Digest Lines: 47 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 388, Message 4 of 12 In article gast@cs.ucla.edu (David Gast) writes: > The practice of not using 9xxx as telephone numbers was not > nation-wide. My parents' phone number assigned in 1959 was 99x-9xxx. > A friend of mine had the number 99x-99xx. (And one of the x's in each > number was a zero). Although I did not call collect frequently, I > never had any trouble when I did call collect. Other people also had > 9xxx numbers. Incidentally, 99x were very popular exchanges; for all > practical purposes they have been completely assigned for years. > The old Bell system was not so uniform in its policies and procedures > as we are frequently like to reminisce about. I can tell you from firsthand experience that in smaller SxS CO's (say, 3,000 lines and less) in the Bell System it was so common as to be almost universal that numbers ending in -9XXX be used for: (1) test lines and telephone company offices; (2) coin station lines; and (3) business lines and PBX trunks. In the case of the SxS CO we are dealing with common line finder and connector groups that would require features different from that of residential POTS lines. Such features include but are not limited to: 1. Higher traffic requirements (i.e., more CCS) per line may utilize more than one connector shelf (10 connectors) per 100 terminal numbers. 2. Higher traffic requirements for call origination may utilize ROTS (Rotary Out Trunk Switches) to provide greater than 10 selector and/or outgoing trunk paths per selector digit level. 3. Requirement for message register operation may dictate that lines be placed in common linefinder groups. While greater traffic handling could also be achieved by spreading line assignments through more hundreds groups and leaving unassigned numbers, there was a tradeoff between this technique (which required more SxS shelves) and that of concentrating lines in smaller groups (which were usually associated with ROTS). Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?" VOICE: 716/688-1231 {boulder, rutgers, watmath}!ub!kitty!larry FAX: 716/741-9635 [note: ub=acsu.buffalo.edu] uunet!/ \aerion!larry