From telecom-request@delta.eecs.nwu.edu Tue Aug 29 17:28:51 1995 by 1995 17:28:51 -0400 telecomlist-outbound; Tue, 29 Aug 1995 13:21:54 -0500 1995 13:21:44 -0500 To: telecom@eecs.nwu.edu TELECOM Digest Tue, 29 Aug 95 13:21:00 CDT Volume 15 : Issue 362 Inside This Issue: Editor: Patrick A. Townson Re: Area Code Crisis -- A Different Viewpoint (Fritz Whittington) Re: Area Code Crisis -- A Different Viewpoint (Clive D.W. Feather) Re: Area Code Crisis -- A Different Viewpoint (Tony Harminc) San Francisco Area Codes (Peter Mansfield) Re: Allnet Tries to Hide Adult Services (Dave Levenson) Re: IntegreTel/VRS Billing-Bulk Block Procedure (Randal L. Schwartz) Re: Snakes In The Net - Adult Services Auto-Block Numbers (Michael Fumich) Re: Wideband SATCOM Nets to Support WWW (Tom Hicks) Re: V&H Questions (Les Reeves) Re: V&H Questions (John N. Dreystadt) Re: V&H Questions (Stu Jeffery) TELECOM Digest is an electronic journal devoted mostly but not exclusively to telecommunications topics. It is circulated anywhere there is email, in addition to various telecom forums on a variety of public service systems and networks including Compuserve and America On Line. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. Subscriptions are available to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@eecs.nwu.edu * The Digest is edited, published and compilation-copyrighted by Patrick Townson of Skokie, Illinois USA. You can reach us by postal mail, fax or phone at: 9457-D Niles Center Road Skokie, IL USA 60076 Phone: 500-677-1616 Fax: 708-329-0572 ** Article submission address only: telecom@eecs.nwu.edu ** Our archives are located at lcs.mit.edu and are available by using anonymous ftp. The archives can also be accessed using our email information service. 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A suggested donation of twenty dollars per year per reader is considered appropriate. See our address above. All opinions expressed herein are deemed to be those of the author. Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- In comp.dcom.telecom rbarry@iol.ie (Richard Barry) writes: > fritz@mirage.hc.ti.com (Fritz Whittington) wrote: >> There is an extremely interesting document available at: >> http://www.open.gov.uk/oftel/oftelwww/oftcons.htm >> which explains how the UK intends to handle the area-code and number >> shortage problems, in a very flexible and user-friendly way. > I wouldn't suggest that anyone looking for an ideal numbering strategy > look at the UK model (except on a what not to do basis!) The reason > the authorities there are entering a pretent public consultation > process is because they have done so much damage and screwed up so > badly up to now. Agreed, but they now *seem* to be trying to correct for that. OFTEL took over the numbering plan only last year, from BT. A large part of the problem seems to have been inherited from the fact that a country so relatively small was divided into so many 'area' codes: "The present geographic scheme - now using 01 numbers - was designed by the Post Office in the 1950s and is based around 638 areas, each of which has a code. With the exception of London and some other major cities, all these areas are of similar size." This gives the potential of 800 000 numbers for some small towns of a few hundred people. > There is no long term numbering strategy in the UK - it changes > virtually every year, which is great for the printing industry! Since > "PhONEday", the UK has enough numbering space for about 8 billion > phone lines, which means that phone numbers are much longer than they > need be, under any population / user terminal growth scenario. "NOBODY will *ever* need more than 64K of memory." --Eubanks, ca. 1976 "NOBODY will *ever* need more than 640K of memory." --Gates, ca. 1981 > You can't tell which part of the country an area code is located from the > first digit or two, as one can in virtually every other European > country -- (eg area code 01232 is Belfast, Northern Ireland while 01233 > is in Kent in the South East of England). ... > Mobile phone numbers, paging, and premium rate numbers are found all > over the numbering space. The article is very critical of this, and suggests that an "02" series of *much larger* area codes be overlaid on the current "01" series, with only 020-029 used. Presumably, these would be few enough for people to remember their geographical relationship. *BOTH* the 01 and the 02 area codes could be used permissively. Also, "numbers beginning 04 can in future be used for mobile services; 07 for Personal Numbering services; and 08 for special services such as freephone, services charging national calls at local rate and some information services." While I respect your views and agree with many of your observations (mostly the ones I deleted without comment), I suspect that you haven't really read the article thoroughly. Fritz Whittington Texas Instruments, P.O. Box 655474, MS 446 Dallas, TX 75265 Shipping address: 13510 North Central Expressway, MS 446 Dallas, TX 75243 fritz@ti.com Office: +1 214 995 0397 FAX: +1 214 995 6194 Since I am not an official TI spokesperson, these opinions contain no spokes. ------------------------------ In 15.359.5 Richard Barry wrote: > I wouldn't suggest that anyone looking for an ideal numbering strategy > look at the UK model (except on a what not to do basis!) By coincidence, I'd just received the following in email from Nick Leverton, and forward it with his permission: > I liked "Pulp Video"'s sketch last week ... Scene, the National > Lottery draw. The balls drop down one by one, the number > flashes up on the screen, a breathless announcer gasps "1 34 8 > 12 26 38 ... that, ladies and gentlemen, is the new dialing > code for Manchester!". > I think that about sums up Oftel's present credibility problem concerning > lack of planning :-( Clive D.W. Feather | Work: clive@demon.net | Gateway House Senior Manager | Home: clive@stdc.demon.co.uk | 322 Regents Park Road Demon Internet Ltd. | Tel: +44 181 371 1000 | Finchley | Fax: +44 181 371 1281 | London N3 2QQ ------------------------------ rbarry@iol.ie (Richard Barry) wrote: [UK numbering scheme not recommended as a model] > You can't tell which part of the country an area code is located > from the first digit or two, as one can in virtually every other > European country -- (eg area code 01232 is Belfast, Northern Ireland > while 01233 is in Kent in the South East of England). This is not different from North America. And unlike the NANP, where area codes were assigned pretty much at random, the UK codes started out as alphabetics related to the place name. So 01232 (then 0232) was originally 0BE2 - BE for Belfast, while 0234 was 0BE4 for Bedford, 0484 was GUildford, and so on. This broke down after a while, and there was never any way of guessing what the 4th digit would be, but it is the basis for those numbers. > Most European numbering plans have the following characteristics: > *Hierarchical area code structure* (like the US Zip code. While one > mightn't know where Zip 90234 is precisely, even a non-American can > guess that it is on the West coast and probably in California. > Someone who knows California can probably guess it is in the LA area, > etc.) This structure follows on to some extent from the country code > layout (eg all country codes beginning with 3 are in Europe). The French system is nothing like this. The Departement numbers are scattered randomly around the country, so you can't tell where a number is unless you have memorized the list. > *Variable number length* so that cities that outgrow 7 digits can have > 8 digit local numbers. No multiple area code confusion. Small > towns can have even shorter local numbers, if desirable. This is terrible idea, for the one simple reason that telephones don't have Enter keys. So the switch has to decide when you've finished dialing by some means, usually a timeout. Or if the switch is smart enough it may be able to avoid timeouts on certain calls, but the result is inconsistent behaviour. > *Distinctive non-geographic codes* so that anyone can tell a mobile > number or a pager or a premium rate number from a regular phone number > easily. The NANP has this for 900 and such, though there are some local variations (976 and the like are not universal). There is no need to know that yo are calling a mobile number if the mobile user is paying, Indeed many people would consider it a privacy violation for the phone company to tell all their callers what kind of service they have by assigning special numbers to mobiles. Tony Harminc [TELECOM Digest Editor's Note: Actually, telephones do have 'enter' keys or 'carriage return' keys. It is the '#' key located underneath the '9'. Sometimes known as the Octothorpe, the signal from this key is generally understood to mean the end of the dialing string has occurred. For example, try dialing just 0 for the operator, then 0# for the operator and note how much faster the latter connects, since no time-out is needed. Likewise try calling the number to which your calling card is assigned (which allows entry of just the calling card pin rather than the whole number) and after entering the four digit pin then do nothing ... it will time out eventually and process your call. Do it again adding # after the four digit pin and note the difference. If some specified number of digits are expected and required, then the use of # will not affect the timing one way or the other. For example punching in the seven digits of a local call followed by # has no affect whatsoever. A non-working two or three digit combination followed by # will have no affect whatsoever; that is the network will continue waiting patiently for more input from you. But if some two digit combination (for example 72 ro call forward or 67 to suspend transmission of caller ID) is presented and these can also serve as the first two digits of some longer combination, then adding # will make a difference, and the network will go right to work on what (two digits or other less than 7/11 combination) you have entered. So why don't we have telephone numbers of any length with the understanding that when the subscriber has finished giving the instructions, a # is used to indicate conclusion. The network would then process what had been given in the proper context. PAT] ------------------------------ Reading Mark Cuccia's interesting and informative history of the Mexican hacks and TWX, this reminded me of something I read in Carl Moore's history.of.area.splits in the Telecom Archives a while back dealing with the introduction of area code 318 in 1951, which I'm interested in finding out more about. Carl writes: > 415/318 California, 1951 > 318 was used for San Francisco only, during the Englewood (N.J.) > Customer DDD Trials; Oakland remained in 415. Sometime before 1957, > 318 was reclaimed for future use, and San Francisco returned to 415. > 504/318 Louisiana, 1957 > 318, used earlier for San Francisco, had been reclaimed by this time. Furthermore, in 1959, according to Carl Moore's file, 415 did a *three-way split* with West Central California moving to 408 and North West California moving to 707, with the San Francisco Area retaining 415 (which, as we know, later split again to form 415/510). So, do any historians out there know anything more about these DDD trials, specifically why a new NPA was allocated, and then reclaimed several years later. Also, was it a full cutover, or simply some kind of optional 'overlay' where either 318 or 415 could be used to reach San Francisco? If San Francisco was still in 318 for some time after 1951, why then did it return to 415, which was obviously nearing capacity, as it split three ways a few years later? Finally, are there any other known cases such as this, where an area code is split and is later reclaimed, or changed back to the former code or somehow reshuffled (apart from another split or overlay)? Incidentally, the above three-way split of 415 in 1959 seems to indicate that the current three-way split planned for Chicago cannot claim to be the first, especially since the Chicago split/reorganization is being implemented over about two years, and not all at once. (I don't think anyone actually claimed that it *was* the first, just that that it was the only one that anybody could think of!) Peter Mansfield Sydney, Australia Tel: +61 2 256 7940 Fax: + 61 2 256 7777 Email: Peter_Mansfield@australia.notes.pw.com ------------------------------ Eric Bennett (bennett@hpel.umd.edu) writes: > It seems to me unfair to have a product the cost of which cannot be > determined until the purchase is made. I think a mechanism should > exist for dynamically charging calls. Imagine how long the teleslime > would last if that $5/min popped up on a display before the call was > connected. 900 information providers are required, under current law, to voice a `disclaimer announcement' during the initial 24 seconds after answering. This announcement must state the name of the information provider, and the price of the call (stated as a per-call amount, or a per-minute amount, as appropriate). The announcement must then state that the caller may disconnect NOW to avoid charges. This announcement normally ends with a beep signifying the beginning of the chargeable call. If the caller disconnects before the beep, no charge is made. The information provider generally pays the long distance carrier for these calls. > What other option is there? 500s are a billing lottery unless you > trust who/what ever you are calling. Folks who can't get through to > 500s being used as intended will come to my attention much sooner than > people who are "only making a long distance call" to some landmine > 500. For telecom resellers, PBX administrators, COCOT-owners and such, there is generally no other option than to completely block calls to 900, 976, and now, 500 numbers. If credit-card billing is accepted to these numbers, then 0+ calls to such numbers may be allowed if billed-number screening is also effective. Dave Levenson Internet: dave@westmark.com Stirling, NJ, USA Voice: 908 647 0900 Fax: 908 647 6857 ------------------------------ >>>>> "Randal" == Randal L Schwartz writes: > Do they read the ANI to you? If they do, we now have another way > of getting ANI. > [TELECOM Digest Editor's Note: Yes, they read the ANI back but only after > you have indicated you want the line blocked. I guess you could use them > to find out the number on lines which are unidentified as long as you or > the owner of the line don't object to being blocked from Integratel charges. > The way they phrase it is cute: "As a courtesy, your local telephone company > forwarded your number to us at the time they connected your call. The > number we are blocking is xxx-xxx-xxxx." No, you can get ANI without taking any action. Here's the sequence: 1-800-4BLOCKME wait through first message (cannot be interrupted) as soon as the menu starts: 3 2 (you can do these fast together) "As a courtesy, your local... xxx-xxx-xxxx" *if you press "1" here, you get blocked, "2" you don't. Just hang up. Thank you, Integretel, for giving us ANI from an 800 call, even if it takes a minute and we have to hear your name four times. :-) ·_ Name: Randal L. Schwartz / Stonehenge Consulting Services (503)777-0095 flying Email: Snail: (Call) PGP-Key: (finger merlyn@ora.com) Web: My Home Page! Quote: "I'm telling you, if I could have five lines in my .sig, I would!" -- me ------------------------------ It was mentioned in a previous article that Integretel (a misnomer if you ask me), has 800-425-6256 (800-4BLOCKME) available to block any adult services calls that may be billed by them. American Telnet, another company of this type also has one. That number is 800-204-2569. This number must also be dialed from the number that you wish blocked. Their Customer Service number is 800-460-0307. I don't know if these numbers will block 500 calls however. I will post more as they become available. Michael L. Fumich / E-Mail: <3311835@mcimail.com> / V-Mail: 708-461- 5770 ------------------------------ Kramer <102564.2255@CompuServe.COM> writes: > Is there a market to support the wideband download of data (imagery, > video, bulk files, etc.) from www sites based on narrow band requests? > Considering developing asymetrical net using DBS satellites (similar > to Spaceways concept) to provide 23MBS downlink to 20cm antennas and > embedded terminals with 14.4 teresstial and/or satcom uplinks for > request channel. Price targets $1/2k per terminal. $3/4 per 15 > second @ 23MBS. What do you think? Hughes Network Systems has such a beast for sale, called DirectPC. It provides up to 400Kbps commited rate, but I think it can burst up to 3 Mbps. 14.4K POTS link is available for outgoing traffic. I'm not sure if there are plans to add more user data bandwidth. I think price is between $1/2K per terminal. I think they sell the Internet connectivity package under the title of "Turbo Internet". So it is technically feasible. Not sure about the market. Tom Hicks thicks@hns.com ------------------------------ Douglas Frank (dougf@startel.com) wrote: > Can anyone tell me where V&H coordinates came from, and how they > actually represent distances in the U.S.? > Does anyone know how to translate V&H coordinates (such as those found > in Bellcore's LERG data) into standard lattitude and longitude? I am > creating a real-time network map, and need this translation. The > answer in any form would be appreciated, though programming code or > algorithm form would be best. This question (albeit a good one) appears often enough that it might deserve it's own place in the FAQ {hint, hint}. I can provide the equation used to compute miles, given two V&H numbers. It is in most IXC and/or intra-lata tariffs, mine is circa 1984. I realize this is not what you want, unless you happen to have the exact longitude and latitude of one end. Even with that you only get a distance, but no vector. And let's don't even consider whether or not the equation covers the Earth's curvature. There is a program, called NPA, which will do what you want. To get all the goodies, you must register it. The unregistered version is not exactly crippled, but it *will not* give you what you want. Here is the info on the latest version: NPA for WINDOWS <04Jul95> - Comprehensive area code (NPA), prefix (NXX), and city name locator. Contains 90,000,000 ZipCode to NXX mappings ranked by frequency of occurrence, county name, estimated county population, lat/long for each NXX for inter-city or inter-NXX mileage calculation, NXX use type (landline/cellular), city time zone, and more for over 20,000 cities in the USA & Canada. Nearly 60,000 NPA/NXXs in all! All fields except lat/long & county population are key searchable! Tie US ZipCodes & Canadian Postal Codes to NPA/NXXs. Print, file output, and Optional Data Export. Most complete area code program you've ever seen! I tried to find an contact number for the author, but this is a WINDOZE program, and everything but the file description is in the form of a Windows .hlp file. He also has a DOS version. The author goes by the name of PC Consultant, and is located in Houston. This is an excellent program. I have been using the DOS version for a couple of years. E-Mail me if you need contact info, although I think Pat may have it at hand). ------------------------------ In article , dougf@startel.com says: > Can anyone tell me where V&H coordinates came from, and how they > actually represent distances in the U.S.? > Does anyone know how to translate V&H coordinates (such as those found > in Bellcore's LERG data) into standard lattitude and longitude? The V&H system was invented by Bellcore (O.K. Bell Labs at the time but the current organization is Bellcore. This is an attempt to turn the U.S which is a curved area on a sphere into a flat plane with the least amount of overall error when doing distance calculations. Works reasonably well. Each V or H represents .1 miles so distance = sqrt((V.Orig - V.Dest) ^ 2 + (H.Orig - H.Dest) ^ 2 ) / 10 Some locales have special rules if the result is a small number but 99% of the time, the above formula gets the right answer. Serious errors crop up when using this for locations at the fringe, (i.e. AK to HI). The code to convert V&H to K&L (Latitude/Longitude) is interesting (I did this for a company I used to work for). If you are willing to buy the code, call Lynn-Arthur Associates in Ann Arbor and see what the license fee is. Sorry but I did that work for them and cannot share the results. To reproduce it, you would need access to the original formulas from Bellcore for converting K&L into V&H and be good at writing algorithms backwards. Be warned, I had to do some iterative loops to approximate the answer and this is harder than it looks as you are doing things in two dimensions. Have fun. John Dreystadt ------------------------------ Attached is a C program that will do what you want. I don't know anything more than what is here. I think it was posted in a news group, so use at your own legal risk. I have compiled it and it works fine. Going the other way is a bit more complicated. Probably the simplest way is by successive approximation. Good Luck. ----------------------------------------- /* * ll_to_vh.c -- computes Bellcore/AT&T V & H (vertical and horizontal) * coordinates from latitude and longitude. Used primarily by * local exchange carriers (LEC's) to compute the V & H coordinates * for wire centers. * * To compile: cc -o ll_to_vh ll_to_vh.c -lm * * This is an implementation of the Donald Elliptical Projection, * a Two-Point Equidistant projection developed by Jay K. Donald * of AT&T in 1956 to establish long-distance telephone rates. * (ref: "V-H Coordinate Rediscovered", Eric K. Grimmelmann, Bell * Labs Tech. Memo, 9/80. (References Jay Donald notes of Jan 17, 1957.)) * Ashok Ingle of Bellcore also wrote an internal memo on the subject. * * The projection is specially modified for the ellipsoid and * is confined to the United States and southern Canada. * * Derived from a program obtained from an anonymous author * within Bellcore by way of the National Exchange Carrier * Association. Cleaned up and improved a bit by * Tom Libert (tom@comsol.com, libert@citi.umich.edu). * * CASH REWARD for copies of the reference papers, or for an * efficient (non-iterative) inverse for this program! (i.e. * a program to compute lat & long from V & H). */ #include #include #define D_TO_R(d) (.0174532925199433*(d)) /* Degrees to radians */ /* Polynomial constants */ #define K1 .99435487 #define K2 .00336523 #define K3 -.00065596 #define K4 .00005606 #define K5 -.00000188 /* PI in various forms */ #define M_PI 3.1415926535898 #define M_PI_2 1.57079632679489661923 /* EX^2 + EY^2 + EZ^2 = 1 */ #define EX .40426992 #define EY .68210848 #define EZ .60933887 /* WX^2 + WY^2 + WZ^2 = 1 */ #define WX .65517646 #define WY .37733790 #define WZ .65449210 /* PX^2 + PY^2 + PZ^2 = 1 */ #define PX -.5559778217300487 #define PY -.3457284881610899 #define PZ .7558839026055240 /* COS77 is actually cos(76.597497064) */ #define COS77 .231790398 #define SIN77 .972765753 #define K6 6363.235 #define K7 2250.700 #define K8 12481.103 #define K9 (K8*COS77) #define K10 (K8*SIN77) #define EVER ;; ll_to_vh(lat, lon, iv, ih) double lat, lon; int *iv, *ih; { double lon1, lat1, latsq, x, y, z; double e, w, vt, ht, v, h, cos_lat1; /* Translate east by 52 degrees */ lon1 = lon + D_TO_R(52.); latsq = lat*lat; /* Use Horner's Rule for efficiency (standard trick for computing polynomials) */ lat1 = lat*(K1 + (K2 + (K3 + (K4 + K5*latsq)*latsq)*latsq)*latsq); cos_lat1 = cos(lat1); x = cos_lat1*sin(-lon1); y = cos_lat1*cos(-lon1); z = sin(lat1); e = EX*x + EY*y + EZ*z; w = WX*x + WY*y + WZ*z; e = e > 1.0 ? 1.0 : e; w = w > 1.0 ? 1.0 : w; e = M_PI_2 - atan(e/sqrt(1 - e*e)); w = M_PI_2 - atan(w/sqrt(1 - w*w)); ht = (e*e - w*w + .16)/.8; vt = sqrt(fabs(e*e - ht*ht)); vt = (PX*x + PY*y + PZ*z) < 0 ? -vt : vt; v = K6 + K9*ht - K10*vt; h = K7 + K10*ht + K9*vt; #ifdef DEBUG printf("v = %17.16f, h = %17.16f\n", v, h); #endif /* DEBUG */ *iv = v + .5; *ih = h + .5; } /* * Converts lat/long in ddmmssXdddmmsssY format * to separate latitude and longitude in radians. */ int dms_to_lat_lon(char *dms, double *lat, double *lon) { int deg1, min1, sec1, deg2, min2, sec2; char dir1, dir2; int num; fflush(stdout); num = sscanf(dms, "%02d%02d%02d%c%03d%02d%02d%c", °1, &min1, &sec1, &dir1, °2, &min2, &sec2, &dir2); if (num != 8) { fprintf(stderr, "\"%s\": illegal format\n", dms); return(1); } *lat = M_PI*(60.*(60.*deg1 + min1) + sec1)/(180.*3600.); if (dir1 == 'S') *lat = -(*lat); *lon = M_PI*(60.*(60.*deg2 + min2) + sec2)/(180.*3600.); if (dir2 == 'W') *lon = -(*lon); return(0); } main() { long lat_d, lat_m, lat_s; long lon_d, lon_m, lon_s; double lat, lon; int v, h; char loc[256]; printf("Computes V&H (vertical and horizontal) coordinates\n"); printf("given latitude and longitude.\n\n"); printf("Example (Ann Arbor, MI):\n\nEnter location: 421700N0834445W\n"); printf("v = 5602, h = 2919\n\n"); for (EVER) { printf("Enter location: "); gets(loc); if (feof(stdin)) break; dms_to_lat_lon(loc, &lat, &lon); #ifdef DEBUG printf("lat = %17.16f, lon = %17.16f\n", lat, lon); #endif /* DEBUG */ ll_to_vh(lat, lon, &v, &h); printf("v = %d, h = %d\n", v, h); } } -------------------------------------------------------- Stu Jeffery Internet: stu@shell.portal.com 1072 Seena Ave. voice: 415-966-8199 Los Altos, CA. 94024 fax: 415-966-8456 ------------------------------ End of TELECOM Digest V15 #362 ******************************