25:
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the time if a caller had no dial tone, the caller could not dial at all. After it was over, the area emergency services filed complaints, and were heard. Shortly afterward the 305-550 exchange came into being. The first number on it was 305-550-9100 (for Y100 radio station). Due to the issues involved because of the "Last
Contest", this may have been what caused the creation of the choke exchanges.
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connection rather than overwhelming the rest of the local telephone network. Other local exchanges have a limited number of direct trunks (junctions) to the choke exchange, which may only serve one or more customers, such as a radio station contest line, which may experience many simultaneous calls.
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advertised their "Last
Contest". The top prize was an automobile. Since the advertising lasted over a month, there were a very large volume of calls when they announced for people to call in. There were so many calls that the local exchanges ran out of dial tones. This caused major issues since at
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A central office might only have physical plant resources to handle ca. 8% of allocated telephone numbers, based on historical call traffic averages. A choke exchange has trunk facilities to other exchanges designed in a manner that high call volume is handled through the
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designed to handle many simultaneous call attempts to telephone numbers of that exchange. Choke exchanges are typically used to service telephone numbers of
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One of the early choke lines (exchanges) was instituted due to a widely advertised contest by a local radio station in the Miami/Fort
Lauderdale area.
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But instead of calls being overflowed to main or tandem routes shared with other calls, the unsuccessful callers receive a
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from their local or tandem exchange. If the calls were overflowed to the tandem route, the caller would receive a
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from the exchange serving the radio station, and the sudden peak would disrupt calls between other customers.
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Higdon, John (1989-09-22). "Re: Prefix '520' For Los
Angeles Radio Stations".
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caller and contest lines of radio stations and event ticket vendors.
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Telephone exchange designed to handle many simultaneous call attempts
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Examples of choke exchanges in North
America have included:
49:. Unsourced material may be challenged and removed.
892:"TELECOM Digest Guide to Special Prefixes/Numbers"
885:
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826:"Re: Prefix '520' For Los Angeles Radio Stations"
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109:Learn how and when to remove this message
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942:Telephone numbers in the United States
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47:adding citations to reliable sources
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13:
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666:Minneapolis/St. Paul, Minnesota
34:needs additional citations for
898:(Mailing list). Archived from
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770:Raleigh-Durham, North Carolina
1:
890:Leibold, David (1990-11-24).
810:
136:
927:Telephone exchange equipment
7:
937:Telephone numbers in Canada
824:Higdon, John (1989-09-25).
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601:Vancouver, British Columbia
169:
10:
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283:Philadelphia, Pennsylvania
705:Orange County, California
679:Charlotte, North Carolina
484:San Francisco, California
421:
247:
458:Pittsburgh, Pennsylvania
397:Providence, Rhode Island
160:common-channel signaling
249:Los Angeles, California
164:Signalling System No. 7
757:Sacramento, California
536:New Orleans, Louisiana
309:Baton Rouge, Louisiana
783:San Diego, California
653:Boston, Massachusetts
510:Little Rock, Arkansas
425:(770 from 1995-1998)
640:Nashville, Tennessee
523:Louisville, Kentucky
471:Milwaukee, Wisconsin
384:Lafayette, Louisiana
43:improve this article
805:Routing in the PSTN
588:Rochester, New York
445:Baltimore, Maryland
370:St. Louis, Missouri
223:Seattle, Washington
210:Birmingham, Alabama
744:Memphis, Tennessee
236:New York, New York
127:telephone exchange
932:Telephone numbers
867:comp.dcom.telecom
834:comp.dcom.telecom
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731:Fort Worth, Texas
718:Buffalo, New York
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575:Montreal, Quebec
562:Cincinnati, Ohio
497:Toronto, Ontario
423:Atlanta, Georgia
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58:"Choke exchange"
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410:Omaha, Nebraska
296:Cleveland, Ohio
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162:(CCS), e.g.,
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54:Find sources:
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32:This article
30:
26:
21:
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904:. Retrieved
900:the original
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819:
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368:
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149:reorder tone
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41:Please help
36:verification
33:
921:Categories
906:2010-11-05
811:References
493:–870, –872
137:Motivation
131:talk radio
69:newspapers
863:Newsgroup
830:Newsgroup
185:Location
182:(NPA–NXX)
153:busy tone
99:July 2016
799:See also
356:Michigan
339:Illinois
170:Examples
871:Usenet:
865::
838:Usenet:
832::
792:WHYI-FM
352:Detroit
335:Chicago
83:scholar
873:
840:
85:
78:
71:
64:
56:
433:–741
258:–520
158:With
144:choke
125:is a
90:JSTOR
76:books
779:–570
766:–860
753:–766
740:–535
727:–787
714:–644
701:–977
688:–390
675:–570
662:–989
649:–931
636:–737
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610:–750
597:–280
584:–222
571:–790
558:–749
545:–390
532:–260
519:–571
506:–433
480:–478
467:–799
454:–333
441:–481
419:–741
406:–962
393:–224
380:–920
365:-969
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331:–591
318:–550
305:–499
292:–578
279:–263
266:–787
245:–520
232:–955
219:–421
206:–741
193:–432
62:news
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45:by
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882:^
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849:^
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354:,
337:,
121:A
909:.
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843:.
112:)
106:(
101:)
97:(
87:·
80:·
73:·
66:·
39:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
