private line magazine and e-zine back issue text archive. Caution when using any material here which is now very much dated.
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THE SECOND PRIVATE LINE E-ZINE! -- (private line #12 -- Vol. 3#3)
by Tom Farley
http://www.privateline.tv
Thanks to Damien Thorn, Peter Shipley, Naftali Bendavid & especially Nancy!
I. Editorial Page
II. Updates and Corrections
A. Cryptography article addition
B. Free payphone calling in the 916 -- the saga continues
C. More on the GTD-5
D. The Controlled Environmental Vault (CEV)
E. Canadian Telecom Part 3? -- Yes and No III.
Letters
A. Ruminations on phone books and phone outages
B. TWX is not a candy bar
C. A nice letter from Anonymous in Minnesota
IV. An Introduction to Prison Phone Technology -- by Tom Farley
A. A brief overview
B. Three different call processing approaches
1. Class of service approach
2. Generic switch utilizing custom software
a. Close up of one switch: NACT's 120LCX
3. Dedicated system using PC technology
4. Typical Call processors' anti-fraud features
a. Call blocking on a permanent basis
b. Call blocking on an as needed basis
c. Limiting long distance carriers
d. Flash hook prevention
e. Rotary dial acceptance
f. Limiting automated message attempts
g. Conference call prevention
C. The federal Inmate Telephone System (ITS)
1. Introduction
2. Letter from jail
3. Discussion and speculation
4. Federal Bureau of Prison (B.OP.) Time Line
5. Discussion continues
6. ITS Account Report
7. A report on ITS from Jail
8. Bibliography
V. A short history of independent telephony in America -- with an attitude! -- by John Hyde
IV. _private line_ Table of Contents & back issue order information
I. EDITORIAL PAGE
October 1, 1996
Greetings again from Isleton, California. The deadline for subscribers to request refunds or back issues has passed. _private line_ as it existed now fades into history. I'll still sell back issues, though, and there is a list of these at the end of this e-zine. Thanks so much for your consideration and support. I'm still trying to find a publisher so don't give up hope on a hardcopy _private line_ just yet. Having said that, I am offering printouts of the _private line_ e-zine for $5.00 apiece. It looks very sad compared to the old magazine, however, it does keep me going as a paper publication; fully protected under the First Amendment and it does give me something to send to those without net access.
I've got lots and lots of new subscribers, by-the-way, to this e-zine. Thanks much. Just as a recap, this e-zine was started to mollify the former subscribers of _private line_, a way to give them something to read since the magazine needed to fold. It seemed logical then to freely distribute to anyone who wanted it, after all, I started putting the text of my back issues up on the net in 1994. I've always felt this material should be freely distributed. Check out the etext archive at Michigan for _private line_ as well as privateline.tv:
etext.archive.umich.edu/pub/Zines/PrivateLine
It's my hope to get much more posted to privateline.tv as time permits. I'm also getting a t-shirt produced. The cost will be $15.00 including shipping to U.S. residences. I'll e-mail you all the details when I get the design up at the web site. The goal will be to ship the shirts a few weeks before Christmas.
I wish you all the best. The electronic door is always open.
Tom Farley
II UPDATES AND CORRECTIONS
A. Cryptography article addition
A friend said encryption or cryptography should have been defined at the start of Rich Adam's article last issue. Okay. Please copy and paste, if you will, this standard definition into last issue's text:
Cryptography involves methods to prepare cryptograms, messages incomprehensible to everyone but "those with the legitimate means to reproduce the original plain text." Cryptography comes from the Greek words _kryptos_ meaning 'hidden' and _graphein_ meaning 'to write.' Converting a plain text message into a cryptograph is called encrypting, more specifically enciphering or encoding.
B. Free payphone calling to the 916 -- the saga continues
I hedged a little last issue about free calling with Citizens' Telecom payphones. Free payphone calling to anywhere in the 916 from Ryde, Walnut Grove and at a payphone west of Courtland still existed when I wrote the article. These telephones use, respectively, the 776 and 775 prefixes. Their C.O.'s were upgraded around September 1, 1996, consequently, free calling, for the most part, came to an end in the California Delta. Before those switches were changed, though, I had a great experience that celebrates the mysteries of the telephone system.
Several weeks ago I needed to call Isleton from Walnut Grove. I hadn't done that before and I was curious to see what would happen. Was it a local call? Could I call for free, like I did elsewhere in the 916? Or would it prohibit a local call, like it used to do in Isleton? You see, the only exception to free calling within 916 was calling another phone in the local prefix. Like calling the 777 prefix from a Citizens payphone in Isleton. A little voice always came on the line saying the call "requires a coin deposit, please hang up, deposit 20 cents . . ." etc., etc., etc.
Anyway, I tried calling in my usual way without putting in any coins: 1-916-777-4420. I got prompted immediately to hang up and deposit coins. "Oh, well," I thought "I do need to call Isleton so I don't mind paying for it. No ACTS so it must be only 20 cents." I put it my coins, dialed the number and guess what? It connected me AND returned my coins! Can you believe that? I tried it several times in the weeks after and it always returned my deposit. Isn't life good? But strange. Got another payphone story? Send it in . . .
C. More on the GTD-5
Carl Navarro (cnavarro@wcnet.org) writes in to say that the 'D' in GTD-5 stands for digital. Thus, the full name is General Telephone Digital-5 (class 5 office) Electronic Automatic eXchange. Got it? Carl goes on to note the one near him "is a 1984 or so vintage. No ISDN ever, but caller ID was available 4 years ago. Rumor has it that the district manager was the only one who had it since it was not tariffed :).
"GTE Ohio hides number announcement in the xxx-1206 numbers. If you call LD to 419-353-1206 I think you'll get 1000HZ tone, but locally you'll get number announcement. This also works on 285-1206 and 823-1206 (GTD-5 RSU).
"I got to see the RSU for a GTD-5 about 3 months ago. Wow! It is large by today's standards, about the size of an OMNI PBX. I think the architecture is 4 line ccts (stations) per card [the literature below states 8, ed.] , and the cards were about 6x8 inches. It seemed kind of strange, since the office it replaced was a Leich 100 (old Automatic Electric X-Bar). The Battery plant took up most of the space the old Leich stood in, and the RSU took up 2 bays for 800 stations! It is T1'd to our main C.O. (which was built in our old manager's office). Talk about a trip, here we went from an old step- by-step toll office (with SATT*) to digital. The silence was deafening :)
"I believe the GTD-5 is available for software upgrades only and, perhaps, some limited additions. GTE-Ohio is using AT&T switches. I think that AT&T bought the manufacturing rights to the GTD-5, or something like that, but it is pretty obsolete. In our area, they are not even putting RSU's to our toll center for an exchange that is less than 10 miles away. Instead they went to an AT&T 5ESS."
Thanks, Carl, for the informative note. I went back to the old _GTE Automatic Journal_ and found some interesting stuff on the GTD-5. Check out the article "GTD-5 EAX -- A Family of Digital Switches" in the September, 1979 issue and "Architecture of the GTD-5 EAX Digital Family" in the July, 1980 issue. Let's take a quick look at this switch, based upon those two introductory articles.
The GTD-5 was an early digital central office switch designed especially to take care of remote units. How early? Its control architecture was based on a 8086! Automatic Electric offered a large or small version. The larger unit, called _the large base unit_ or _LBU_ in A.E.'s crippled terminology, had a capacity of 1,300,000 CCS (one hundred call seconds), 360,000 call attempts an hour and 300,000 directory numbers. Serving 2,000 to 145,000 lines, depending on configuration, it could also provide class 4C toll service. The small base unit, by comparison, could serve 500 to 20, 000 lines, with 160,000 CCS, 65,000 call attempts an hour and host up to 40,000 directory numbers. Toll service was not supported with the SBU. Both base units could stand alone or serve a number of remotes.
The RSU or Remote Switching Unit Carl referred to is a "small switching system designed to serve outlying communities and as a replacement for community dial offices." Installed at central offices controlled by the GTD-5, each RSU could serve up to 3,000 lines with a capacity of 19,200 CCS. I think two to thirty two RSUs could be supported over T-1 links by one GTD-5. Each remote switching unit could, in turn, serve up to 8 Remote Line Units (RLUs) and 4 Multiplexer Units (MUs). Don't choke on this alphabet soup just yet.
An RLU is a "larger concentrating pair-gain unit with a capacity of 768 lines." A multiplexer, in other words, for larger but distant local loops. Finally, the multiplexer units or MUs served smaller local loops. No more than 96 lines could be accommodated. Common channel signalling circuits over T-1 lines tied all this equipment together. Thus, one GTD-5 could serve a *very* large wire center. (Read a little about Rural Area Network Design in _private line_ Number 8 and about Community Dial Offices in P.L. #1.)
To summarize, then, the GTD-5 was a good example of early distributed intelligence and switching in the telephone system. I thought at one time the switch was obsolete but see below. GTE stated in 1979 the GTD-5 could "evolve gracefully into the network of the 1980's and beyond." But it is doubtful Automatic Electric engineers envisioned this switch providing ISDN or full CLASS features. Most companies that can afford to have replaced these switches and moved on. Roseville Telephone, for example, finally pulled the last lines off a GTD-5 this year, retiring the beast for another AT&T 5ESS.
In July of 2000, Micktee@aol.com (http://www.agcs.com) wrote in to say that the GTD-5 is not obsolete and that it does support all CLASS features and ISDN. He spent a "good deal of the 1990's designing and developing it." He wrote further that GTE and BC Tel/TELUS (Western Canada)"continue to invest heavily in upgrades to the softwared and hardware, and into line and trunk growth."
*Carl Navarro went on to explain that "SATT stands for Strowger Automatic Toll Ticketer. Picture a 23 inch relay rack 8 feet tall and that holds 3 ticketers. Remember, these are all relay controlled! Now mount about 80 of these devices in 4 rows, add 200 rotary switches that make a 45 step by 5 contact spin every time someone calls for a ticketer, let them dump to 8 paper tapepunches and on a Wednesday night (the kids always called home before drinking on Thursday!) and you have some incredible noise :)
Okay, even more detail now! On June 26, 2002, Tom Cain wrote in to say,
"Tom --Just stumbled across your site searching for some history; its great! I enjoyed reading a few items about GTD-5 and Roseville Tel. I was part of the design team on GTD-5 from 1982 -- 1986. We cutover the first GTD-5 in Banning, California in 1982. I and 2 other engineers tested, commissioned, and cutover the first GTD-5 Remote Switch Unit. The base unit was in Savannah, MO with the RSU about 15 miles away in Helena, MO. We were there for about 5 months and I got damned good at driving the route between installations at high speed! One day we had been making excellent progress with testing going well when the remote just went dead. We could not talk to the remote from the base for nothing. I hopped in the rental car and drove the cable route out to the remote. About halfway there I found the farmer with his backhoe along side the road!"
"Roseville Tel was also a great company to work with. I spent time in their main C.O. doing field service on their ITT 1210 and then returned a couple years later to work on the GTD-5 in Citrus Heights with an RSU at Roseville Main."
"Your site stirred up some great memories; thanks!!! If you want to see the next great C.O. switch, visit http://www.santera.com. (external link)"
Regards, Tom Cain
Miscellaneous GTD-5 links:
http://www.agcs.com/supportv2/techpapers/gateway.htm (external link, now dead)
http://gasint.com/page/gtd5.htm (external link)
D. The controlled environmental vault (CEV)
I wrote about controlled environmental vaults in _private line_ Number 7 (Volume 2, Number 4, July/August 1995). A C.E.V. is an underground structure that often houses telephone equipment . The one I went into and took pictures of for that issue's Outside Plant article housed a 5ESS. In effect, it is a small central office underground. These inconspicuous, buried buildings allow companies like RTC to distribute its switching capacity more equally around its serving area. Your only clue to a C.E.V.'s location is its top -- a four by four foot flat steel panel two or three feet off the ground, rising out of the earth like a green, squarish mushroom.
It turns out that Roseville Telephone Company installed the first C.E.V. in California back in 1986. Here's a history of that vault, reprinted with permission, from Steve Chanecka's book, _The History of The Roseville Telephone Company_:
"'The company is looking at the serving area west of Antelope Road by using a controlled environmental vault which meets the concerns of nearby residents since it is asethetically appealing. We will use it to house a remote switching unit which will serve this area. Plant from our central office to the 'CEV' will be fiber optics and from the remote location to the subscribers will use normal copper wire. Basically, this unit will serve the same function as a mini-substation, but will be underground and therefore does not detract from homes in the neighborhood.'
"Ned Kindelt explained the CEV in more detail in a late 1985 article in _Line Chatter_. 'A CEV is a central office located underneath the ground. The equipment vault is 10 feet, six inches wide and 24 feet long, and will contain a remote unit in Citrus Heights for control. The remote switch unit will be wired for 4,608 lines.' In addition, the CEV had air conditioning, a dehumidifier, an automatic sump pump and an alarm system.
"The use of CEVs was pioneered by Roseville Telephone in California. The state's first one was placed on Lichen Drive in Citrus Heights in late 1986. The engineering, splicing and installation was a long, arduous process, according to project director, splicer Jim Hood. He reported in the October 1986 _Line Chatter_
'Our first CEV is almost past history. This has been a very difficult project for many departments. This vault is powered from the Citrus Heights central office by our first fiber optic cable. Our second vault, already a work-day reality for some departments will be located on Antelope Road near the Foothill Christian Center. To say that this has been a learning experience is being tactful.'
"That first CEV may have been challenging but the concept was a lifesaver for Roseville Telephone. Faced with an aggressive expansion of residential housing in the Antelope area of Citrus Heights, the company's conduit capacity to run copper cable from its Citrus Heights central office under Interstate 80 was insufficient for the long term. Had there been no other option, the company would have faced costly construction to increase its underground conduit system.
"The CEV approach solved this. Rather than making the conduit system larger, the use of fiber optics resulted in the cable bundle running through the conduits being smaller in diameter. Thin, very high capacity fiber optics connected the central office and the CEV. The far thicker copper cable ran from the CEV to the customer. Fiber optics enabled much more information to be transmitted through a much smaller bundle of wires. Leon Bower, director of outside plant engineering, explained to fellow employees why CEVs and fiber optics made sense in the fall of 1985:
'If you read local papers, you are aware that the area roughly north of Antelope Road, between the railroad and Watt Avenue in Sacramento County, is about to be developed. They are projecting between 13,000 and 14,000 new homes in the Antelope Urban Reserve in the next 20 years. For the area west of the freeway we are projecting a requirement of 16,000 lines for that 20 year period.'
'To serve this area with conventional copper cables would require an investment of some $3.5 million at today's cost in outside plant alone. Underground conduit systems would have to be reinforced, at a very high cost, to accommodate the fourteen 1500- pair, 24 gage feeder cables needed. A fiber cable will cost us about $102,000. . .'
"Since 1986, 12 more CEVs scattered evenly throughout the company's service have placed impressive digital switching power and data transmission capacity close to the users at an economical price. Moreover, all but one of the company's 13 operating CEVs at the end of 1994 were located inside utility right- of-ways. The company did not have to buy the site of the CEV or obtain permits to put them in the ground. Most people are not even aware of where the CEVs are placed."
It is my understanding that each vault is backed up with alternative routing, that is, a separate fiber comes in from two directions to the vault. A single accident will not cause any vault to go down. The _History of the Roseville Telephone Co._, by the way, is a fascinating read and an important contribution to independent telephony. RTC is the 23d largest telephone company in America and one of the most progressive. The book is over four hundred pages in hardback. $20 in the U.S. plus $3.50 shipping. Call (916) 786-1117. There's a discount for orders of five or more. Or order by mailing from the following: Telephone Book, Roseville Telephone, P.O. Box 969, Roseville, CA 95678. And make sure to visit their telephone museum at 106 Vernon Street in Roseville from 10:00 to 4:00 p.m on Saturdays.
E. Canadian Telecom Part 3? -- Yes and No
Mark J. Cuccia (mcuccia@mailhost.tcs.tulane.edu), a frequent contributor to Pat Townsend's Telecom Digest, wrote a great article on Canadian telecom history and independent telephony that you must check out. It's entitled 'History'. Check out Stentor, Bell Canada, Independents - Some History' and it's over at the T.D. digest under:
http://massis.lcs.mit.edu/telecom- archives/archives/history/stentor.bell-canada
I reviewed Canadian telecom in _private line_ Number 8 and P.L. Number 9.Those two articles focused on the current scene, with an emphasis on the major telcos. I wanted to write Part 3 on Canadian telecom history and the independents, however, I never found the time. Marks' article is a better piece than I could ever write. It includes a great internet resources list. I asked Mark about hardcopy resources and he sent me this reply:
I just recently received a copy of the 1972 hardcopy book (out of print) called "Singing Wires" which is about the history of the telephone in Alberta. I don't know if the URL's given in the article on Canada I sent to Telecom Digest are exactly still valid, and I did have a follow up on the roles of Teleglobe and Telesat which appeared in TD shortly after. Many of the Canadian telcos have a brief history section on their webpages, too!
One of the 'larger' independent group owners in Canada, AGI, Amtelicom Group Inc, now has a page, http://www.knservu.ca/~jimc/index.html, and 'subpages'. This group holds Amtelicom, Manitoulin Island Telco, and now Coldwater Communications.
I haven't yet formatted it in ASCII (I originally did it as a Word Perfect for Windows 'chart'), but I did a numerical and alphabetical listing of the 'non-Stentor' telcos and their serving exchange locations and (NPA)-NXX codes for those telcos in Ontario and Quebec. I want to eventually send it to Dave Leibold in Toronto, http://www.io.org/~djcl/phoneb.html, for his pages of Canadian (and elsewhere) numbering and code information.
Some of the early dates in my submission to TD might not have been exactly correct. Some of the info in there was written from memory, particularly reading an article in a 1950's issue of Bell Telephone Magazine, on the Trans-Canada Telephone System. In that AT&T journal, I remember reading that Bell Telephone of Canada had extended as far west as Alberta in the earlier years of this century. I had thought that the three prairie provinces had 'socialized' telephone service in their respective provinces 'by' the 20's, but it was actually a bit earlier. AGT was formed in Alberta by the province government to take over telephone service away from Bell Canada, around 1908. It had been a while since I had read the 1950's article on TCTS in Bell Telephone Magazine.
One thing I like about the 'net' is that from now on, when there are current ownership changes in telephone co's or just about ANYTHING, it will be easy for ANYONE in the world to access the more recent histories, without having to leave their home or desk! I can find out about new area codes, or histories of telephone co's, etc. just by going to the proper websites, rather than cranking rolls of microfilm at a public or private library halfway across town (at least I live in a 'big ugly' city... some of New Orleans is very nice and historical, but other areas look bombed out; but I don't have to travel from 'the country' to the 'big city' to do most old-style research)... I don't really have to 'wait' for photocopies to come thru the post office mail on things I am researching... I can get some faxes or now even e-mail or clicking on a link on 'the web'...
BCEs "Northern Telephone" (their URL is mentioned at the end of my Canada article in TD) mentions a history book of some kind, as does the telco of Cochrane Ontario in their webpage (I think I mentioned their URL), but I haven't purchased their books yet.
Take a look at http://www.sciencetech.com/EN/FR.html for info on the French version of "Invisible Empire", published in 1993. It is supposed to be published in English eventually, I've been told 1995 or 96 or 97... The full table of contents is on that website. It is a TWO VOLUME HARDBOUND deep history of Canadian Telephony!
Nigel Allen (and Dave Leibold) have been active on the Internet (or its predecessor including Bulletin Boards) for quite some time. They also supply info to comp.dcom.telecom (Telecom Digest), and both live in Toronto. Their personal webpages have a lot of good pointers to various other internet reference sites on telephony, Canadian & US, and other parts of the world!
-----------------------------------
III. LETTERS
A. Ruminations on phone books and phone outages
Hi Tom,
Thanks for the zine - I've read it with interest. One of your articles [about the telephone books] sounded quite familiar. Same here. 5x7 book, 69 white pages of actual phone numbers with 50 pages preceding it with general informational garbage and another 70 pages of yellow pages - all the numbers for GTE's section of northeast Missouri,which comprises 17 towns and the surrounding areas, utilizing 17 prefixes. Monroe City is the largest single-prefix geographic region in GTE's local area and it has a population of 2,700 and probably not too many more phones.
Best I can tell, it's the same here for most of GTE's northeastern Missouri area all the way down to Wentzville, which is about a half hour outside of St. Louis and is where GTE's toll center is for this area. FYI, Wentzville is about 1:45 drive from here. GTE has a fiber that goes down to there, but from all appearances, it's a series-run too.
[As far as Isleton loosing long distance for a day], it was August 16, 1996 here - and at least three times before that this year alone. Someone down near Wentzville cut the fiber yet again, and for nearly six hours this time (due to lightning in the area of the cut -usually it's more like four) all we could dial were numbers in Monroe City's 735 exchange. Our company has a tie line between our PBX in our Monroe City plant and the one in our Palmyra plant which doesn't follow that fiber line, so I could dial through to the Palmyra side and observe the same problem there, only it was 769 numbers that they could dial. I suspect it was the same throughout all of GTE's local area.
Our FX [foreign exchange] line to Hannibal (Southwestern Bell territory) also ran over the fiber down to Wentzville and back up (even though there's a fiber directly between here and there - only 20 miles away.... grrr...) and it was down too. I found out about it because I was on the internet and had just composed a response to an e-mail that I had gotten half an hour earlier, and got a "Destination Host Unreachable" error. After doing some pinging, I figured that the 56k line that our provider had running to Monroe City went down, so I tried to get hold of him. Since he's in Hannibal, I first tried dialing into our company's switch and dialing out the Hannibal FX trunk. I got a reorder tone.
That was odd, since normally the worst I'll get will be a expensive route warning tone... I then tried getting a trunk directly - same thing.Then I decided to spend some money and dial from home. Same reorder tone. I tried an 800 number. Reorder tone. By this time, I knew what had happened, having went through it before. The difference is that this time it had happened at night and knocked out my internet connection, so I was pissed... I decided to go into work and spend my now free time composing a letter to the Missouri Public Service Commission regarding GTE's poor (or non-existent) emergency routing, and composed a side-letter saying that I wanted our T1 to our new Hannibal plant routed directly to Hannibal and not over that fiber so that whenever GTE went down, we could go out Southwest Bell. (I'm sure that made GTE happy... <g>). Yesterday I got a call from GTE's local area supervisor, who (quite politely and diplomatically and supportively) relayed GTE's corporate position to me. To paraphrase, and to use different words than the supervisor used, they basically said "Complaint acknowledged. Status Quo will be maintained. Thank you for calling.". Grrr...
So anyway, thought you might like to know you're not the only one... Cya, Fred
fmcclint@nemonet.com" "Fred McClintic"
B. TWX is not a candy bar
Hi:
Do you have any info (which may have already appeared in Private Line, or may be appearing later on in Private Line) regarding the old (1960's/70's era) of TWX and 800?
I know that the special TWX area codes have been 510, 610, 710, 810, 910. TWX back in the 1960's and 70's, using these area codes, was actually switched over to the Bell System Telephone Network. There was also '3-row' TWX back in the 60's and earlier 70's, using their own telephone area codes, and there were 0XX/1XX codes used in routing TWX.
TWX in Canada (which doesn't exist at ALL anymore) used 610. Other Canada services which also began to use 610 have all been cut over to 600, as 610 became southeast PA's additional area code in 1994. TWX in Canada always remained a part of the Telecom-Canada telephone network, until TWX in Canada was discontinued in late 1994, although 600 continues to be used for ISDN and caller-pays cellular.
TWX had an assistance operator dialed as 954-1212, 910-954- 1212 (for a 4-row assistance operator in the US) and 610-954-1212 (for a 4-row assistance operator in Canada). There was also '130' and '140' used in the network for routing something to a TWX Assistance Operator.TWX Directory was reached with 555-1212, 910-555-1212 (for TWX directory in the US) and 610-555-1212 (for TWX directory in Canada).
The 510 thru 910 codes were 'flipped' to 015 thru 019 for routing 4-row to 4-row calls, so as not to force them thru a 'converter', although I was told that the 'flipping' of the code was done only on routing 3-row to 4-row calls, so AS to force them thru a 'converter'. This code flipping was done in the switching network, not dialed by the TWX customer.
Prefixing a geographic POTS telephone area code with a '0' (i.e. 0212) was to be used for 4-row to 3-row calls via a converter. This code prefixing was done in the switching network, not dialed by the TWX customer.
There was also 013, and for Canada, 014. I don't know what these 0xx codes were when used for TWX, nor how they were used. I could GUESS that they were used for TWX directory operators, but I don't know for sure.
And I've been trying to compile a complete numerical listing of the OLD (1960s/70's) TWX N10-NNX code assignments, and what 'POTS' NPA-NNX they corresponded to.
For old 1960's/70's 800, I do have a list of the old geographic assignments of the 800-NNX interstate inward WATS codes, and I do know which were the original 1966 codes. But there were some additions made throughout the late 1960's and the 1970's. I don't know what year any particular code would have been added. And 800- 261, one of about three 800-NNX assigned to the Toronto (416) area for their inbound 800 calls was 'cut' over to 800-387 sometime around 1980. I don't know the exact year nor the reason why!
And while I do have a general understanding of the old 800 (interstate) switching and routing, using the 1NB codes (and 08B) codes, I am trying to find *WHICH* '1N' codes were used for which 800-NNX codes or cities! Do you happen to have some of this old obsolete numbering and routing information on TWX and 800 as it was in the 1960's and 70's?
I've tried asking people at Bellcore about the history of TWX & 800 numbering, but they don't have the time to go through the records, with all of the new area codes being planned for, these days, all the time! And AT&T's Archives charges a lot of money for them to look up info, and when I inquired (also asking for an estimate of how much it would be), I got a cold response, "We are unable to supply you with the information you requested".
The old 800 & TWX numbering/routing information was in the old AT&T Long-Lines "Traffic Routing Guide"... 800 (Inward WATS) in section 2; International (IDDD) info in section 12; TWX info in sections 13 (4-row <==> three row machine conversions), s.14 (info on TWX "Switching Plan" US, 710/810/910), s.15 (TWX US 510), s.16 (TWX Canada 610). The only thing is to FIND an intact Traffic Routing Guide from the 1970's (or later 1960's)....
Thanks. If you can find anything more, I'd be most appreciative!
MARK J. CUCCIA PHONE/WRITE/WIRE: HOME: (USA) Tel: CHestnut 1-2497WORK: 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) LA (70128)|cellular/voicemail
Anyone have an intact Traffic Routing Guide from the 1970's to loan mark? TWX or Teletype Writer eXchange was a AT&T teletype switching service that placed calls automatically to any other teletype machine. An early data network, in other words, in fact, some of the first computer time sharing was conducted in the mid- 1960's over the TWX network. The genesis of TWX began when AT&T bought the Teletype Corporation in October, 1930. The TWX system started operating in 1931. Teletype made the equipment while AT&T leased the teletypewriters and sold the service. Calls were placed over AT&T's direct distance dialing network. All calls were manually dialed at until TWX switching became automatic in the United States in 1962 and extended into Canada into 1963. AT&T sold TWX in 1972 to Western Union.
For more information, look up this URL over at the Telecom Archive: http://massis.lcs.mit.edu/telecom- archives/archives/history/western.union For now, here's a little excerpt from the mid-sixties _Grollier's Encyclopedia of Popular Science_. It details how a telegram, an important teletypewriter application, was sent:
"In automatic transmission by the printing method, a device called a teletypewriter, or perforator, is used. It looks like a typewriter with three rows of keys. As each key is pushed down in turn, it punches a certain number of holes, forming a distinctive pattern, in a narrow paper tape passing through the machine. Sometimes the tape passes directly into the transmitter from the perforator; sometimes the operators feed it in at their convenience when a certain number of messages are to be sent.
"Little pins in the transmitting machine press lightly against the tape paper. As the pins come to the holes in the tape, they move down into them just enough to operate small electric switches. The switches cause current impulses to be transmitted over the telegraph wire; the impulse pattern corresponds to the arrangement of holes in the tape. The impulses operate an automatic typewriter, called a teleprinter, at the receiving end of the line. The messages appear in capital letters on long strips of paper, which are then cut and pasted on telegraph blanks.
"In preparing a message, the operator types a routing signal at the beginning of each telegram. After she has typed the message on the perforated tape, it passes through an automatic transmitter. The coded symbol causes an 'electric brain' at the high speed message center to route the message to its destination area. Here the automatic teleprinter receives the message and typewrites it.
"Many industrial firms and public agencies use some form of teletypewriter or teleprinter exchange service, such as Western Union Telex. Each Telex subscriber is provided with a teleprinter, an associated dial unit and a nationwide directory of other subscribers with their Telex numbers. A subscriber can get in touch with another subscriber by dialing his number; the connection is completed automatically in eight seconds anywhere in the United States. Canadian and Mexican subscribers can also be dialed. Subscribers in seventy nine countries overseas can be reached through interconnection with overseas Telex networks that are compatible with Western Union Telegraph transmission speeds."
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