From ptownson@massis.lcs.mit.edu Mon May 12 03:59:18 1997 Return-Path: Received: by massis.lcs.mit.edu (8.7.4/NSCS-1.0S) id DAA25447; Mon, 12 May 1997 03:59:18 -0400 (EDT) Date: Mon, 12 May 1997 03:59:18 -0400 (EDT) From: ptownson@massis.lcs.mit.edu (TELECOM Digest Editor) Message-Id: <199705120759.DAA25447@massis.lcs.mit.edu> To: ptownson Subject: History of TWX/Canada Early 1980's Our regular participant Mark Cuccia was quite busy last week preparing for us another of the outstanding history articles he sends along from time to time. Thanks Mark! PAT Date: Fri, 09 May 1997 12:01:18 -0500 From: "Mark J. Cuccia" Subject: HISTORY/twx.canada.early.1980s HISTORY/twx.canada.early.1980s Here is another old document being transcribed for the TELECOM-Archives. I was recently *loaned* a copy of an original by one of my friends now retired from Bellcore/Bell-Labs, who had started with Bell-Labs in the 1950's. This document regards the Numbering and Routing of TWX in *Canada* in the early 1980's. By that time, TWX in the US (which had been sold over to Western Union from AT&T circa 1970/71) had been *completely* removed from the AT&T/Bell-System switching/routing network, thus on to WUTCO's *own* private/dedicated network also used for WUTCO Telex and Telegram service. TWX in Canada, however, continued to be owned by the local/provincial telephone companies within Canada, and were thus numbered/dialed and switched/routed over the Canadian portion of the North American DDD *Telephone* Network. The TWX Service in Canada began *for the first time* circa 1962, although CNCP (later known as Unitel), the *telegraph* company in Canada, had started automated *telex* service in Canada in 1956. TWX in the US (3-Row/60-wpm, 5-level Baudot/Murray punch code) was started by AT&T/Bell in 1931, but it was a network that was *manually* switched by cordboard operators, over a network and numbering plan separate and distinct from the telephone network. In 1962, US TWX was automated by *integrating* it within the NANP and DDD network. Existing TWX customers (which were located only in the continental US) were given 10-digit NANP telephone numbers based on their geographic telephone NPA code and a central-office code of a major #5XB switch in their city. Also in 1962, a new 4-Row/100-wpm (and 8-level ASCII code) TWX service was begun in the (continental) US in addition to Canada, which would be Canada's first time ever having TWX. The new 4-Row/100-wpm TWX machines did have 10-digit geographic telephone numbers for internal routing, but for the 'public', they were identified by 10-digit numbers using SAC's (Special Area Codes) of the N10 format. 4-Row/100-WPM TWX in the US had SAC NPA's 510, 710, 810 and 910. Canada's SAC for TWX was 610. After TWX in the US was completely removed from utilizing the AT&T/Bell network in the early 1980's, SAC's 510, 710, 810 and 910 were no longer considered 'assigned' as NPA's by AT&T or later Bellcore. However, Telecom-Canada needed to continue to recognize these SAC NPA's as TWX routing codes for routing Canada-to-US TWX calls. Later on, Bellcore's NANPA did assign the N10's as geographic telephone NPA's (510 to the split of 415 in California in 1991, 910 to the split of 919 in North Carolina in 1993, 810 to the split of 313 in Michigan in 1993; and 710 was assigned to the US Federal Government in the early 1980's, for their own special functions). Since Bellcore was now assigning the N10's as geographic "POTS" NPA's, they requested that Canada 'swap' 610 for 600. The N00's (such as 800, 900, 700, and now 500) have also been used as service-specific non-geographic SAC's. SAC 610 in Canada was also used by the Telecom-Canada companies for DATALINK service, starting in 1982. In 1988, the major competitive carrier (Unitel, now known as AT&T-Canada) and the Canadian international carrier (Teleglobe) were also assigned some 610-NXX codes (by Telecom-Canada) for some of their own (non Telecom-Canada OTC) special ISDN and Data services and functions. Canada did 'swap' 610 for 600, which took effect in a 'flash-cut' on 1-October-1993, thus Bellcore-NANPA was able to re-assign 610 as a geographic telephone NPA, to the split of southeast Pennsylvania's 215 which took effect in permissive dialing in January 1994. Canadian TWX Service itself was discontinued by Stentor in the Fall of 1994. The 600 SAC continues to be used by the local/provincial telcos of Stentor, and others, for Data/ISDN functions, international inbound special services (Teleglobe), satellite mobile telecom services (Telesat/TMI), and even for "caller-pay-airtime" cellular (B-side cellular provided by Mobility-Canada, the association of cellular subsidiaries of the wireline LEC's -- both of Stentor and incumbent 'independents'; A-side cellular provided by Rogers-Cantel), etc. (i.e., Microcell 1-2-1; Telezone; etc.) The NXX codes within SAC 600 are presently assigned to carriers, by the Canadian Numbering Administrator of the Canadian Government's "Industry Canada" Department, similar to the way Bellcore-NANPA presently assigns the NXX codes to carriers within SAC's 900 and 500, and the way Bellcore NANPA *USED* to assign 800-NXX's to carriers prior to the beginning of 800 number-portability in Spring 1993. The Canadian industry is planning on a 'third-party' telecom numbering administrator for intra-Canada or Canada-specific NANP resources, similar to the way the NANP as a whole is presently seeking an 'independent third-party' numbering administrator. This document itself was prepared by the TransCanada Telephone System, to become known as Telecom-Canada circa 1982/83, and then changed its name to Stentor circa 1992/93. The document is in English, but I would assume that there is also a French version as well. Any notes and/or comments of mine inserted within the document will be enclosed by square brackets [], and I will have some additional comments at the end of this transcription. DISCLAIMERS: In the *original* document, some of the spellings, grammar or text appeared to *ME* to be somewhat confusing or convoluted. It might have been that the original author if the document was a French-speaking Canadian. I have read and re-read the original document, and there are a few spots where I have *slightly* changed the text in this transcription. *MOST* of this transcription is the *original* text of the document. Also, I have put some of my own notes in square brackets within the transcription, as mentioned above. And, there were some charts, graphs and maps in the original. In some of them I have tried to use ASCII-text 'art' to 'reproduce' them here, but in other cases, I have summarized such 'figures' or 'charts'. I *HOPE* that I haven't mis-spelled anything; I *HOPE* that my grammar is corrct; and I *HOPE* that my own descriptions in here are clear, concise, choherent and complete. And if anyone would like to know exactly what I have slightly modified from the original text, please feel free to contact me. Also, the switchname CLLI codes indicated in some of the lists/charts here weren't indicated in the original document, but came from the 1981/82 edition of the "Distance Dialing Co-ordinating Handbook", an annual 'inventory' of all (or most all) of the toll/tandem switches in the North American DDD Network. MARK_J._CUCCIA__PHONE/WRITE/WIRE/CABLE:__HOME:__(USA)__Tel:_CHestnut-1-2497 WORK:__mcuccia@mailhost.tcs.tulane.edu|4710-Wright-Road|__(+1-504-241-2497) Tel:UNiversity-5-5954(+1-504-865-5954)|New-Orleans-28__|fwds-on-no-answr-to Fax:UNiversity-5-5917(+1-504-865-5917)|Louisiana(70128)|cellular/voicemail- ------------------------------------------ TransCanada Telephone System PRACTICE #453-3020-100 Issued: 1982-04-01 NETWORK SYSTEMS TransCanada Telephone System TWX NETWORK NUMBERING PLANS AND ROUTING PATTERNS CONTENTS of SECTIONS: 1. GENERAL 2. TWX SWITCHING PLAN 3. TWX NUMBERING PLAN 4. NNX-CODES, LINE-NUMBERING ASSIGNMENTS, AND CODE-CONVERSION 5. SERVICE CODES 6. CANADIAN ROUTING PATTERNS 7. MANUAL TWX 8. INTERCEPT 9. WESTERN UNION NETWORK 10. TCTS INTERCONNECTION WITH WESTERN UNION 11. ROUTING PLAN: CANADA-TO-USA 12. ROUTING PLAN: USA-TO-CANADA 13. EMERGENCY RE-ROUTING 1. GENERAL 1.01 This practice describes the TransCanada Telephone System (TCTS) Teletypewriter (TWX) Network, the numbering plans and routing patterns, and provides an overall view of the Western Union interconnection. 1.02 The Canadian and Western Union Systems are completely compatible, using 100-speed machines. In this system, speed-converters are not necessary. [When 3-Row/60-WPM TWX still existed in the US during the 1960's (TWX was *owned* by AT&T as well as being switched/routed via the AT&T DDD network) and 1970's (US TWX now owned by WUTCO but still being switched/routed via the AT&T DDD network), there was a speed/mode converter located in Montreal for connections between (4-Row/100-WPM) Canada TWX and any 3-Row/60-WPM TWX customers in the US. I don't know if there were any speed/mode converters in any other major Canadian switching locations for such TWX calls between Canada and the US. If there weren't, there were several major switching cities in the US which had such speed/mode converters for calls between 4-Row/100-WPM TWX (Canada and US) and any remaining 3-Row/60-WPM TWX terminals in the US, and thus if the cross-border call didn't normally route via Montreal, it would route across the border via some other major Canadian switching city, with the speed/mode conversion being handled via some major US switching city.] 2. TWX SWITCHING PLAN 2.01 The TWX Network in Canada is served on the switched DDD Telephone network. In the USA, a dedicated switched message/data network is provided by Western Union. The Western Union interconnection has three Gateway offices into Canada: Vancouver, Toronto and Montreal. 3. TWX NUMBERING PLAN 3.01 The TWX Service is assigned 10-digit numbers within a single Special Area Code (SAC) covering all of Canada. The SAC for Canada is 610. 3.02 Each subscriber is assigned to a telephone central office arranged for outward DDD with Automatic Number Identification (ANI). 3.03 A typical TWX number would be 610-421-1234. The first six-digits are theoretical numbers. The first three-digits (SAC code) identifies the call to the machine as a TWX service call. The next three-digits (NNX) designates the TWX central office that serves the called subscriber. These six digits (610-NNX) are code-converted to the geographic telephone NNX of the telephone central office on the routing chain. Six-digit translation is needed to direct the TWX calls to completing offices. The last four digits of the number (the line-number) is the TWX subscriber identification in the serving central office. 3.04 The TWX 610-NNX codes are grouped by geographical location within Canada. The first digit or the first two-digits of the NNX code designate the general location within Canada of the called subscriber. TABLE-A GEOGRAPHICAL AREA BY NNX CODE ASSIGNMENT: 610- Canadian Major NNX Geographical Switching Code Area City 1NX (routing codes) Montreal #1 PQ (class-1, MTRLPQ0201T, #4A-XB) 2NX Atlantic Provinces Montreal #1 PQ (class-1, MTRLPQ0201T, #4A-XB), or Halifax #1 NS (class-3, HLFXNS0101T, #4A-XB), or St.John #2 NB (class-2, STJHNBSU02T, SP-1), or Cornorbrook #2 NF (class-2, CRBKNF0202T, SP-1) 3NX Ontario and Quebec Toronto #7 ON (class-2, KNTNON0107T, DMS-200) 42X Quebec Montreal #1 PQ (class-1, MTRLPQ0201T, #4A-XB) 44X Quebec Montreal #1 PQ (class-1, MTRLPQ0201T, #4A-XB) 45X Overseas Montreal #1 PQ (class-1, MTRLPQ0201T, #4A-XB) 49X Ontario Toronto #7 ON (class-2, KNTNON0107T, DMS-200) 5NX Quebec and Ontario Montreal #1 PQ (class-1, MTRLPQ0201T, #4A-XB) 6NX Manitoba Winnipeg #1 MB (class-2, WNPGMB0101T, #4A-XB) 7NX Saskatchewan Regina #2 SK (class-1, REGNSK0602T, SP-1) 8NX Alberta Calgary #2 AB (class-2, CLGRAB2102T, SP-1) 9NX British Columbia Vancouver #2 BC (class-2, VANCBC0104T, #4A-XB) Note: A list of applicable TWX 610-NNX codes is shown in the TWX Rate and Reference Guide for each location. 3.05 Each TWX customer has a ten-digit number, SAC-NNX-XXXX. Customers are required to dial on a ten-digit basis. [Figure-1 is a map of the (continental) US and (provincial) Canada. Alaska and Hawaii are *NOT* indicated, neither are the (northern) territories of Canada - Northwest Territories and Yukon. Mexico is not shown on the map, neither are the NANP Caribbean locations. These areas never did have TWX, although they did have Telex, provided by the telegraph companies or telegraph subsidiaries of the telephone companies in those locations.] [The 610-NNX groupings are shown on the Canadian portion of the map. Also shown are the geographic regions of 710/810/910 for the US, and also indicating 510 as somewhat of an 'overlay' to the entire 48-states of the US. TWX SAC 510, during the AT&T/Bell days of TWX, was for 4-Row TWX in the smaller towns throughout the entire (continental) US, and identified locations which were routed via the 'general' DDD network rather than the dedicated AT&T TWX Switching Plan. SAC's 710/810/910 identified 4-Row TWX in cities served by the dedicated AT&T TWX Switching Plan of directly connected #5XB serving central offices.] [The original AT&T geographic locations of 710/810/910 are indicated on this map. SAC 710 covered those states presently served by NYNEX, SNET and Bell-Atlantic, including DC. SAC 810 covered those states presently served by BellSouth and the Ameritech states of Ohio, Michigan, and Indiana except for the northwest corner near Chicago. SAC 910 covered those states presently served by Pac*Bell(CA)/Nevada*Bell, US-West, Southwestern-Bell, and the Ameritech states of Wisconsin, Illinois, and the northwest corner of Indiana near Chicago.] 4. NNX CODES, LINE-NUMBERING ASSIGNMENTS, AND CODE-CONVERSION 4.01 The numbering plan uses individual NNX codes for the larger rate-centres and "Basket" NNX codes for all others. 4.02 The basket code groups several rate-centres within a single NNX code and distinguishes between them by the line-number assignment. 4.03 The line-number assignments within the basket code are grouped by individual tens-block of numbers, and all customers are assigned within a line-number block allocated to their home rate-centre. Example: Office 'A' has been assigned 610-839. Offices 'B' and 'C' will home on this rate-centre, and a basket NNX code 840 has been assigned to these offices. Office B, for example, would be assigned line-numbers from 9850 through 9859. Then, a line-sort of this 840 NNX code would identify which office or rate-centre the called customer is located. 4.04 TWX subscribers will be identified in each common central serving end-office by one or more special entries on the AMA (Automatic Message Accounting) tape. A separate Office Index or a number of such indexes are assigned for this purpose. 4.05 Where several Office Indexes are available, the larger rate-centres are assigned an individual tape entry, and the remaining rate-centres are grouped in a basket entry. 4.06 Where several rate-centres are grouped in a single Office Index, identification is effected by message-sorting of the original line-number. 4.07 Within the framework of the individual and basket code NNX codes, a separate NNX assignment must be made for the following groups, regardless of the size of the rate-centre. (a) where a subscriber is in a Remote Exchange (RX) to the serving office from a foreign adjacent NPA. (b) subscribers who will ultimately be served from a distant office. The NNX assigned will be associated with the new serving office at cutover. (c) subscribers who originate their traffic through a distant office, but whose incoming traffic routes to their home office, using divided-access line-circuits. In this case, an individual NNX must be assigned to each home office. 4.08 Code-Conversion (a) As the call routes to completion, the last toll switching office capable of six-digit translation will code-convert the 016-NNX-XXXX to a 5 or 7 digit number for completion to the serving local office of the called subscriber. The number of digits to be outpulsed to the terminating office will be determined by local requirements. (b) Note that the TWX 610-NNX of a serving toll-centre and any basket-codes served by the same toll-centre are code-converted to the "telephone" central office code of the serving class-5 local office. o Consequently, any TWX station located in an NPA other than the serving office must have its TWX 610-NNX code-converted to an arbitrary code whose "C" digit does not conflict with any central office code of the serving office, to permit the call to be properly rated on an NPA-to-NPA basis. o In addition, a separate thousand-group (or groups) is assigned to such foreign-area customers. As a result, a match of thousands-digit and arbitrary "C" digit will enable "unauthorized" calls to be blocked. Example: Serving office telephone NNX is: 824 Arbitrary code is: 826 Serving office thousands-digit is '8' FNPA customers' thousands-digit is '7' TWX 610-NNX codes of the serving office are 359, 360. 610-359-8xxx becomes 824-8xxx 610-360-7xxx becomes 826-7xxx However, 610-359-7xxx when converted to 824-7xxx is blocked, since 824-7 is not a valid TWX completing code. 5. SERVICE CODES 5.01 A 6A switchboard located in Montreal will handle all Canadian TWX operator assistance and directory assistance. 5.02 All subscribers in Manitoba, Nova Scotia, Ontario, Prince Edward Island, Quebec and Saskatchewan will dial zero (0) for operator assistance or information (directory assistance). 5.03 The zero (0) access code will be converted to a three-digit arbitrary routing code at all common-control serving offices. This code, 014, will route through intermediate switching points to the Montreal 4AXB, where a recording completing trunk to the 6A switchboard is selected. [In the 1961 document on planning for automation of TWX, it is mentioned that at some future date, TWX operator assistance will be reached by dialing '0', instead of 954-1212. However, I had never seen TWX in the US being instructed to dial '0'. By the 1970's, US TWX dialed 910-954-1212 for the TWX Assistance Operator, employed by WUTCO. This number was for use during weekday/daytime hours; 910-956-1212 was to be dialed at night and on the weekends. Also, in some AT&T numbering/routing documents of the late 1970's and similar Bellcore documents of the 1980's and early 1990's, the code 014 was indicated as "TWX - Canada (only)".] [When TWX in the US was still being routed via the Bell System network, 4-Row/100-wpm customers with SAC 510 might have dialed 954-1212 for the TWX Assistance Operator, but the serving office converted the 954- into 014-. The seven digit string, 014-1212, would then be passed along from one DDD toll switch (#4XB, XBTandem, etc.) to another. The reason was that SAC 510 4-Row TWX customers were routed via the 'general' part of the DDD network (#4XB, XBTandem, etc.), along with 3-Row/60-wpm TWX customers. The final switch in the route which connected to the TWX Assistance Operator needed a way to know if the calling customer was a 3-Row/60-WPM or a 4-Row/100-WPM TWX for completing to the proper 3-Row or 4-Row TWX Assistance Operator. Similarly, although 4-Row/100-wpm TWX customers which were assigned SAC's 710/810/910 were usually routed via the special TWX-Switching-Plan of directly connected #5XB local offices, sometimes calls to the TWX Assistance Operator had to 'spill over' to the 'general' DDD network which was also shared by 3-Row/60-wpm TWX. As such, the 4-Row/100-wpm TWX customer's dialed 954-1212 calls would be code-converted to 014-1212, so as to allow the final switch to distinguish between 3-Row/60-wpm and 4-Row/100-wpm calling TWX's to connect to the proper 3-Row or 4-Row TWX Assistance Operator.] [3-Row/60-wpm TWX customers' dialed 954-1212 calls would be routed along the DDD network, with 954-1212 being passed from one DDD toll switch to another. If a 4-Row/100-wpm TWX customer (which were assigned SAC's 710/810/910) dialed 954-1212 calls, *if that particular call could remain routed within the TWX-Switching-Plan*, then 954-1212 would be passed along the route from one #5XB local office to another.] 5.04 Subscribers in Alberta, British Columbia, New Brunswick and Newfoundland will dial 610-954-1212 for operator assistance, and 610-555-1212 for directory assistance. 5.05 The 6A switchboard operators have access to all TWX machines in Canada and the USA over a tandem trunk group to the Montreal 4AXB office. 5.06 The Canadian 6A switchboard operator can reach the Western Union 6A switchboards at Philadelphia PA and St. Louis MO, by dialing NPA+140. [I wonder if it was dialed 215+140 and 314+140, or if it were dialed 710+140 and 910+140. Western Union US TWX was no-longer a part of the "Bell System" in the US, therefore, the 'telephone' NPA's might have been 'replaced' by using the 'TWX' SAC's by that time. Similarly, I wonder what the US-based WUTCO TWX 6A assistance operators would have dialed at that time to reach the Montreal 6A assistance operator. Would they have dialed 514+140 (which was what was dialed in the 1960's and 70's), or did they dial 610+140? Also, when TWX was automated in 1962, there were *sixteen* 6A Switchboard locations of TWX Assistance Operators in the US. Note that there were only *two* by 1982.] 5.07 Subscribers or operators requiring the services of US directory assistance will dial 910-555-1212. [According to my 1978 WUTCO Telex/TWX directory, US TWX subscribers (which were *still* being switched over the AT&T/Bell-System DDD network for a few more years), dialed 910-221-5151 for directory assistance regarding a US TWX or (WUTCO) US Telex listing. This was an automated directory, something like the customer directly searching information in a computerized database.] [The 1978 WUTCO directory did indicate that US TWX customers would dial 910-555-1212 for an attended directory operator for listings of *TELEX* subscribers in Canada, Mexico or Puerto Rico.] 5.08 US customers or operators will dial 610-555-1212 to reach Canadian directory assistance in Montreal. [The 1978 WUTCO directory did indicate this number for US TWX customers requesting directory listings of Canadian TWX customers, and that this number reached a live attendant. This 610-555-1212 Canada TWX Directory Assistance number was also being indicated in WUTCO directories throughout the 1980's.] [I've checked with the AT&T Operator recently for a 'nameplace' for 910-954 and 610-954. Each one is presently assigned in the NANP telephone numbering network -- 910-954 is assigned to Greensboro NC, while 610-954 is assigned to Bethlehem PA. I wonder if there are any existing telephone customers with -1212 as a line number!] 6. CANADIAN ROUTING PATTERNS 6.01 All TWX machines are of the 4-Row, 100-Words-per-Minute, eight-level ASCII binary-code type. 6.02 All calls are dialed on a full ten-digit basis, and routing will be effected by six-digit translation of the 610 Special Area Code, but first converted by the class-5 local serving office into a Pseudo code, 016. Translations will be executed at the first switcher in the chain capable of 6 or 9-digit translations. 6.03 On direct and indirect trunk groups, the originating toll machine outpulses the ten-digit TWX number. The terminating toll machine will perform the code-conversion of the ten-digit TWX number to the seven-digits or less of the terminating number. 6.04 On direct groups to a terminating toll machine that cannot perform code- conversion, the originating toll machine will code-convert the ten-digit TWX number and outpulses the seven-digits or less of the terminating number. 6.05 On direct groups between a toll machine and a TWX class-5 serving local office that are not in the same toll centre, the toll machine will code- convert the ten-digit TWX number to the seven-digits or less of the terminating number. Note: If the originating office is capable of 9-digit translation, the number can be sent over the network as a normal 'telephone' number: Geographic telephone NPA+NNX. [Figure-2 is a Routing Diagram for intra-Canada TWX routings: (1) Customer dials 610+7D over the loop to the serving Class-5 local office. (2) Class-5 serving office code-converts 610 and outpulses 016+7D to the #4A XB toll office. (3) #4A XB toll office 6-digit translates the 016-NNX and send to terminating toll office. (4) Terminating #4A XB toll office converts 016+6D to the geographic telephone central office code, and routes to the terminating Class-5 local serving office, outpulsing 7-digits or less. (5) Terminating class-5 local serving office connects the called customer.] 7. MANUAL TWX 7.01 Manual TWX service is one where a subscriber does not have access to a common-control office with Automatic Number Identification (ANI). 7.02 The 6A Switchboard operator handles the subscriber's outgoing traffic. 7.03 The subscriber contacts the local-toll operator and requests the Montreal TWX Assistance Operator as: "Operator 991" 7.04 The TWX Assistance Operator establishes the called party connection, and re-calls the originating subscriber on the TWX machine, completing the call. [I would assume that the 'manual TWX' customer called up the local/toll telephone operator from a nearby *telephone*, as TWX machines did *not* have transmitters/microphones for outgoing voice. TWX terminals *did* have a loudspeaker or 'earpiece' for the customer to listen to dial tone, call-progress tones, etc.] 8. INTERCEPT 8.01 The non-working codes and numbers will be routed to the geographic location of the called 610-NNX for intercept. Example: 610-7NX is intercepted in Saskatchewan 610-6NX is intercepted in Manitoba 9. WESTERN UNION NETWORK 9.01 The Canadian TWX service interconnects to the Western Union Network in the United States at the Gateway cities of Vancouver, Toronto and Montreal. 9.02 The Western Union Network has four switching locations: New York, Chicago, Atlanta and San Francisco. 9.03 Each Western Union switching location has a Digital Exchange Switch (DES). These switchers are interconnected over satellite tandem facilities. 9.04 Subscriber loops are connected to the switches by a network of Digital Multiplex facilities. [Figure-3 is a block diagram, showing the four WUTCO DES Switching cities, connected by Westar Satellite with 9.6Kbt uplink/downlink facilities. There are also arrows from the three particular WUTCO DES' pointing out to the specific Canadian city which they have routing to, via dedicated facilities.] 9.05 Two-way calling between Canadian TWX and US Telex *IS* permitted. 9.06 Two-way calling is *NOT* permitted between Canadian TWX and Canadian Telex. [Further down in this document, it is indicated that the 910-420 code is 6-digit screened in Canada, so as to prevent Canadian TWX customers from calling WUTCO's "Infomaster" in Norway IL. Infomaster provided a way for US TWX customers to call *Telex* customers in Canada, Mexico, Puerto Rico, Alaska, etc., *as well, Infomaster was used for US TWX to reach WUTCO Telex customers in the US*. Infomaster would be dialed up 910-420-1212 from a (US) TWX machine, Infomaster would answer and respond with text, and then the TWX subscriber would *type* the called telex number and codes, and other controlling information. Similar ten-digit TWX numbers existed for US TWX customers to reach telex numbers in overseas countries, via various IRC's (International Record Carriers). The ten-digit TWX 'dial-up' numbers were of the N10 format, although some were arranged to be 'toll-free' of DDD/TWX charges to the calling TWX subscriber. The procedure was similar to a telephone subscriber dialing-up an 800/888 or 950 (or "POTS") access number of a particular long-distance carrier (dialing it up with either rotary dialpulse, OR DTMF), connecting to the long distance-carrier's 'dialtone', and then DTMF-ing out the eventual called party's number (and maybe an account, authorization, or card number).] 10. TCTS INTERCONNECTION WITH WESTERN UNION 10.01 The interface point for each Gateway city is: Montreal #1 (MTRLPQ0201T) #4AXB to New York DES Toronto #7 (KNTNON0107T) DMS200 to Chicago DES Vancouver #2 (VANCBC0104T) #4AXB to San Francisco DES 10.02 The interconnection between the Canadian and Western Union Switch is a 4800-baud multiplex facility, Trunk Interface Modules (TIMS), and analogue to digital converters (A/D). Each facility will carry 48 TWX circuits. 10.03 The A/D unit provides eight 4-wire E&M Trunk interfaces, and converts them into one 1200-baud digital stream. 10.04 The TIM multiplexes up to six A/D 1200-baud inputs into one 4800-baud stream to the Western Union DES. [Figure-4 indicates a Canadian Gateway switch, with two wires going in on each side. One side splits through a trunk-circuit, with two wires for the forward direction and two wires for the backward direction. Two additional wires come out of the trunk-circuit, labeled E & M, and through a "Signal Repeater". All of this equipment is indicated as TCTS. All of the wires then go into "Western Union Equipment", at an A/D and TIM, which go to WUTCO's DES at 4800-baud.] 10.05 Western Union has retained the geographic Special Area Codes (SAC) 510, 710, 810, and 910. [Around the mid-1980's, WUTCO actually *abolished* the original geographic meanings of the old AT&T TWX SAC's in the US. WUTCO (US) TWX customers with 10-digit numbers beginning with "SAC's" 510, 710, 810 and 910 could be located *anywhere* in the (continental) US. In addition, the old AT&T geographic meaning of the TWX NNX codes within each SAC became meaningless as well. WUTCO also began to assign US TWX numbers beginning of the format N10-N0X/N1X, and *even* N10-0XX/1XX. i.e., WUTCO TWX 10-digit numbers in the US thus began of the format N10-XXX.] 11. ROUTING PLAN: CANADA-TO-USA 11.01 The Canadian switches will route on a three-digit translation using Pseudo-codes 015, 017, 018 and 019. 11.02 These pseudo-codes represent 510, 710, 810 and 910. 11.03 These code-conversions are to be handled in the Class-5 office. If the Class-5 office cannot perform this function due to equipment limitations, then the Toll machine on which the Class-5 office homes must do the conversions. 11.04 The Vancouver, Toronto and Montreal Gateway switches will forward all TWX calls to Western Union Switches on a pseudo-code and ten-digit basis. 11.05 The TCTS Central Staff Routing Group in Ottawa will issue Canadian-to- United States TWX routing orders by pseudo-code, not the customer-dialed SAC codes. 11.06 All SAC code routing must be routed to the assigned border-crossing interconnect switch. (Except for Winnipeg/Manitoba originated calls to US SAC 910). 11.07 Locations routing via Montreal #1 (MTRLPQ0201T) #4AXB and Vancouver #2 (VANCBC0104T) #4AXB do not require any special routing. 11.08 The Montreal Gateway routes to the Western Union Switch in New York. 11.09 The Vancouver Gateway routes to the Western Union Switch in San Francisco. 11.10 Locations assigned to route via Toronto #7 (KNTNON0107T) DMS200 are specially treated. Regina #2 (REGNSK0602T) SP-1: routes SAC's 510, 710 and 810 on the Regina-Toronto 1HU trunk group; SAC 910 routes into Vancouver. Winnipeg #1 (WNPGMB0101T) #4A-XB: SAC's 510, 710, 810 and 910 routing via the Winnipeg-Toronto 1HU must skip the Winnipeg-Montreal alternate route. Alternate routing is permitted via Regina, with SAC's 510, 710 and 810 routing on the Regina-Toronto 1HU, and 910 routing on the Regina-Vancouver group. Calgary #2 (CLGRAB2102T) SP-1: routes SAC's 510, 710 and 810 on the Calgary-Toronto 1HU trunk group; SAC 910 routes into Vancouver. Alternate routing is permitted via Regina (following the 910 differences as indicated above). 11.11 The Toronto Gateway routes to the Western Union Switch in Chicago. 11.12 Figure-5 is a routing diagram; Figure-6 is a routing table. 11.13 To prevent the interconnection between Canadian TWX and Canadian TELEX, the SAC 910 code is six-digit translated to screen calls to 910-420. This prevents the unauthorized calls via the Western Union INFOMASTER Switch in Norway IL (910-420-1212). The remaining SAC codes are routed/translated on a three-digit pseudo-code basis. [But if 910-420 was screened to prevent accessing Infomaster (910-420-1212) in the United States, so as to prevent Canadian TWX from 'looping-back' to a CNCP Canadian *Telex* subscriber, how did a Canadian TWX subscriber actually reach a WUTCO US Telex subscriber? WUTCO US TWX <-> US Telex calls also were handled by calling up Infomaster, according to the front pages of all of my WUTCO TWX/Telex directories from 1978 and the 1980's! Did Telecom-Canada provide its own 610 "dial-up" number for Canadian TWX customers to connect with WUTCO US *telex* customers? Similarly, did Teleglobe-Canada have any 610 "dial-up" numbers for Canadian TWX to reach Telex subscribers in overseas locations? Earlier in this document, in "TABLE-A, (Canadian) GEOGRPHICAL AREA BY (610)-NNX CODE ASSIGNMENT", 610-45X is indicated as "Overseas, via Montreal #1 PQ". Could it be that Telecom-Canada and Teleglobe had some special ten-digit 610-45X-xxxx numbers to "dial-up" access switches to reach the subscribers of WUTCO's US Telex, and those overseas and international Telex locations?] 12. ROUTING PLAN: USA-TO-CANADA 12.01 Western Union will route calls to the Gateway office associated with the Canadian destination switch, regardless of where the calls originate in the United States. 12.02 Western Union has no requirements for pseudo-codes in their network. Western Union switches will forward all Canadian TWX calls on a 610 and ten-digit basis. 12.03 At the Canadian Gateway office, six-digit translations will route the call over the Canadian DDD network to the terminating end. [Figure-5 is a graphical map of the major toll switches in Canada, and the four WUTCO switches in the US. Arrows and dotted lines indicate the primary and alternate routings for TWX routings between the US and Canada, as described above in sections 11 and 12.] [Figure-6 is the TCTS <-> WUTCO TWX Routing Table:] TO: USA USA CAN CAN CAN 510- 610- 610- 610- 710- 2NX,42X, 3NX, 6NX,7NX, FROM: 810- 910- 44X,5NX 49X 8NX,9NX NF via CRBKNF0202T MTRL MTRL NS/PE via HLFXNS0101T MTRL MTRL NB via STJHNBSU02T MTRL MTRL PQ/ON via MTRLPQ0201T MTRL MTRL ON/PQ via KNTNON0107T TORO TORO MB via WNPGMB0101T TORO (*) SK via REGNSK0602T TORO VANC AB via CLGRAB2102T TORO VANC BC via VANCBC0104T VANC VANC USA via WUTCO (any) MTRL TORO VANC (*) Note: from MB via WNPGMB0101T, to TORO for USA 910-, unless if also via REGN then to VANC for USA 910- 13. EMERGENCY RE-ROUTING 13.01 In the event of a catastrophic failure of border-crossing facilities, a re-route will be initiated by network expansive controls. 13.02 TCAP-43.015 and the Canadian Section of the Network Management Blue Book details procedures and applications of the controls for the cross-border TWX network. [end-of-document] ----------------------------------------- Some further notes/comments of mine.... As mentioned earlier, WUTCO actually abolished the old AT&T geographic meanings of the old TWX SAC's 710/810/910, beginning around 1984/85. The original intent of TWX SAC 510 didn't apply anyhow when WUTCO had completely 'removed' US TWX from the AT&T/Bell network and thus onto its own WUTCO message switching network. Also around 1984/85, the 'central office code' portion of a ten-digit WUTCO US TWX number wouldn't have any 'traditional' geographic meaning anymore, and WUTCO even assigned codes of the form N0X/N1X and even 0XX/1XX! Many of the old ten-digit N10-NNX-XXXX 'dial-up' numbers to reach the services of "Infomaster" (and also the IRC's for TWX calling an overseas Telex) were also *changed* by WUTCO, circa 1984, to same three-digit and four-digit 'short-codes' using the *same* numericals that WUTCO Telex customers had been dialing for *years*. These three/four digit Telex (and then also TWX) 'short-codes' are mostly of the form 10X(X) and 11X(X), although there were a few using other numbericals and combinations. I wonder with these changes in the WUTCO TWX N10-NNX to N10-XXX and the abandonment of 'traditional' geography, beginning in the mid-1980's, how was the Canadian TWX network's interface with WUTCO TWX in the US affected? Several sections of this document show how Canadian TWX had special routings on calls to the US, depending on what US TWX SAC code were dialed! However, by the mid-1980's, the Telecom-Canada network was evolving, in that the #4A-XB and SP-1 toll offices were being cut-over to DMS, and MF Keypulse signaling was being replaced by common-channel signaling. So, *maybe* Telecom-Canada had to *again* modify (or even *completely abolish*) the rigid routing patterns described in sections 11 and 12 of this document, as to *which specific* Gateway city (Montreal/NY, Toronto/Chicago, Vancouver/SF) were used depending on the particular 610-NNX of the Canadian TWX subscriber and the particular SAC N10 of the US TWX subscriber. Circa 1990/91, WUTCO sold TWX *back* to AT&T, in addition to the *WUTCO's original telex* network which WUTCO started in the US in 1958 (incidentally, WUTCO's automated/dial/switched Telex was started in the Northeastern states as an *adjunct* to CNCP's 1956 Telex network in Canada). However, even though AT&T had TWX 'back' (in addition to Telex), the N10-XXX-XXXX numbering plan still has nothing to do with the NANP *Telephone* numbering plan. TWX in Canada was discontinued by Stentor in Fall 1994. *Telex* service in Canada still exists. It is provided by AT&T-Canada, formerly known as Unitel, and prior to circa 1988 as CN/CP. However, I understand that some years back, Unitel stopped providing Telex in Canada as a service to 'new' or 'moving' customers -- only the previously existing customer base was 'grandfathered-in' as long as they remained at the same location. I have a 1991 directory of TWX/Telex/EasyLink, published by *AT&T*. In early 1994, I called up some 800 numbers of AT&T Business services, to inquire if there were a more recent edition of the directory. I was told that the 1991 edition was the most recent, although many TWX and Telex customers listed in 1991 had since discontinued their service. A sidenote here ... Last year, we received a fax from a local business here in New Orleans. The letterhead or fax cover sheet indicated the following: Telephone Number (voice) Fax Number email address Webpage/URL address US Postal Mailing address (P.O.Box, also physical street address) CABLE address Telex number from a US-based IRC's domestic-service (namely WUI, which since the mid-1980's has been part of MCI) Telex (I) number (via WUTCO - or now AT&T) Telex (II) number (TWX) The TWX number was *still* of the *OLD* form of N10-NNX which had been assigned to New Orleans in the 1960's and 70's, when TWX was switched over the AT&T/Bell DDD Network, 810-951-xxxx. FINALLY, I am still looking for the complete master numerical listing of all old TWX N10-NNX codes and the locations (ratecenters/wirecenters) that they were assigned to. I do have a 1978 WUTCO TWX/Telex directory, which also includes Canada TWX 610 listings (as well as Telex listings of Canada, Mexico, Alaska, Hawaii, Puerto Rico). However, by 1978, (US) 3-Row/60-WPM TWX had become virtually non-existent. Remember that 3-Row/60-WPM TWX machines were identified by their actual geographic telephone NPA-NNX codes. 4-Row/100-WPM TWX machines were identified by TWX SAC-based (but still somewhat geographical) N10-NNX codes, although they too did have 'internal' geographic telephone NPA-NNX codes. The telephone NPA-NNX code which was assigned to the 4-Row/100-WPM TWX machine (for internal purposes) was also the telephone NPA-NNX code used for 3-Row/60-WPM TWX in each particular city. I could *TRY* to compile the master listing of N10-NNX codes numerically, but it would take *QUITE* some time, as the directory is a listing of subscribers, alphabetically. And since by 1978, 3-Row/60-WPM TWX was virtually obsolete, I wouldn't be able to 'match-up' the conversions of geographic telephone NPA-NNX's. I *DO* know that the AT&T Long-Lines document called the "Traffic Routing Guide" did have several sections of TWX Numbering/Routing information, from back in its 1960's and 70's editions. Sections 12 thru 16 did include such details on TWX, including a master copy of the N10-NNX codes, listed numerically, and the conversions, locations, and I think the CLLI codes of ratecenters/wirecenters. If anyone happens to have a copy of a circa 1960's/70's Traffic Routing Guide, I would appreciate a copy of the TWX sections, as well as section 2 which included the details of the numbering and routing on the OLD way inward-WATS (toll-free 800) was handled at that time. Thanks! MARK_J._CUCCIA__PHONE/WRITE/WIRE/CABLE:__HOME:__(USA)__Tel:_CHestnut-1-2497 WORK:__mcuccia@mailhost.tcs.tulane.edu|4710-Wright-Road|__(+1-504-241-2497) Tel:UNiversity-5-5954(+1-504-865-5954)|New-Orleans-28__|fwds-on-no-answr-to Fax:UNiversity-5-5917(+1-504-865-5917)|Louisiana(70128)|cellular/voicemail-