BIOC.III BIOC AGENT 003'S COURSE IN [BASIC TELECOMMUNICATIONS] Part III Revised 18-July-84 Word Processed by Tharrys Ridenow [PREFACE]: In Part III, we will discuss the dialing procedures for domestic as well as international dialing. We will also take a look at the telephone numbering plan. NORTH AMERICAN NUMBERING PLAN In North America, the telephone numbering plan is as follows: A) A 3 digit Numbering Plan Area (NPA) Code (Area Code [A/C]) B) A 7 digit telephone number consisting of a 3 digit Central Office (CO) code plus a 4 digit station number. These 10 digits are called the network address or destination code. It is --More--(7%) in the format of: AREA CODE TELEPHONE NUMBER nyx nxx-xxxx Where: n= a digit from 2-9, y= 0 or 1, and x= a digit 0-9 AREA CODES: Check your telephone book or the seperate listing of area codes found on many BBS's. Here are the Special Area Codes (SAC's): 510: TWX (USA) 610: TWX (Canada) 700: New service 710: TWX (USA) 800: Wide Area Telephone Service (WATS) 810: TWX (USA) 900: Dial-it services 910: TWX (USA) The other area codes never cross state lines, therefore each state must --More--(14%) have at least one exclusive NPA code. When a community is split by a state line, the CO #'s are often interchangable (i.e., you can dial the same # from 2 different area codes). TWX: TWX (Telex II) consists of 5 teletypewriter area codes. They are owned by Western Union. These SAC's may only be reached via other TWX machines. Be- sides the TWX #'s, these machines are routed to normal telephone #'s. TWX machines always respond with an answerback. For example, WU's FYI TWX # is (910) 988-5956, the corresponding real number to this is (201) 279-5956. The answerback for this service is "WU FYI MAWA." If you don't want to buy a TWX machine, you can still send TWX messages us- ing Easylink [(800) 325-4112: see TUC's and my article entitled "Hacking Western Union's Easylink"]. 700: At the time of this writing, the 700 exchange does not yet exist. AT&T plans to use it soon, though. They plan to make it a kind of fancy call for- warding service. It will be targetted towards salesmen on the run. To understand how it works, I'll explain it with an example. Let's say Joe Q. Salespig works for AT&T Security and he is on the run chasing a phreak around the country that royally screwed up an important COSMOS system. Let's --More--(27%) say that Joe's 700 # is (700) 382-5968. Every time Joe goes to a new hotel, he dials a special 700 #, enters a code, and the # where he is staying. Now, if his boss decided that he needed to get in touch with Joe, FAST, all he would have to do is dial (700) 382-5968, and it would ring whatever number Joe last programmed it to. Neat, huh? 800: Wide Area Telephone Service (WATS) This SAC is one of my favorites since it allows for toll-free calls. Inward WATS (INWATS): Inward Wide Area Telecommunications Service is the 800 #'s that we are all familiar with. 800 #'s are set up in service areas or bands. There are 6 of these. Band 6 is the largest and you can call a band 6 # from anywhere in the US except in the state where the call is terminated (this is why most companies have 1 800 # for the country and then another for just one state). Band 5 includes the 48 contiguous states. All the way down to band 1 which includes only the states contiguous to that one. Therefore, less people can reach a band 1 INWATS # than a band 6 #. Intrastate INWATS #'s (ie, you can call it from only one state) always have a 2 as the last digit in the exchange (ie, 800-nx2-xxxx). The nxx on 800 #'s represents the area where the business is located. For example, an 800 # 800- 431-xxxx would terminate at a New York CO. 800 #'s always end up in a hunt series in a CO. This means that it tries the first # allocated to the company for their 800 lines; if this is busy it --More--(43%) will then try the next #, etc. You must have a minimum of 2 lines per each 800 #. For example, Travelnet uses a hunt series. If you dial (800) 521-8400, it will first try the # associated with 8400; if it is busy it will go the next available port, etc. INWATS customers are billed by the # of hours of calls that are made to their number. Outward WATS (OUTWATS): OUTWATS are for making outgoing calls only. Large companies use OUTWATS since they receive bulk-rate discounts. Since OUTWATS #'s cannot have incoming calls, they are in the format of (800) *xx-xxxx where * is the digit 0 or 1 which cannot be dialed unless you box the call. The *xx identifies the type of service and the areas that the company can call. Remember: INWATS + OUTWATS = WATS Extender (see part I) 900: This dial-it SAC is a nationwide dial-it service. It is used for taking television polls and other stuff. The first minute currently costs an outra- geous 50 cents and each additional minute costs 35 cents. Bell takes in a lot of revenue this way. Dial (900) 555-1212 to find out what is currently on the service. CO CODES: These identify the switching office where the call is to be routed. --More--(55%) The following CO codes are reserved nationwide: 555 - Directory Assistance 844 - Time ] These are now both in 936 - Weather ] the 976 exchange... 950 - Future Services 958 - Plant Test 959 - Plant Test 970 - Plant Test (temporary) 976 - Dial-it services Also, the 3 digit ANI and ringback #'s are regarded as a Plant Test and are thus reserved. These numbers vary from area to area. [See pt. II for more info on ANI and Ringback.] 950: [Also see pt. I] Here are the services that are currently on the 950 ex- change: 1000 - SPC (SPRINT) 1022 - MCI Execunet 1033 - US Telephone 1044 - AllNet --More--(64%) 1066 - LexiTel 1088 - SBS Skyline These SCC's (Specialised Common Carriers) are free from fortresses! Plant Tests: These include ANI, Ringback, and other various tests. 976: Dial 976-1000 to see what is currently on the service. Also, many BBS's have a listing of these #'s. N11 CODES: Bell is trying to phase some of these out, but they still exist in many areas: 011 - International Dialing Prefix 211 - Coin Refund Operator 411 - Directory Assistance 611 - Repair Service 811 - Business Office 911 - Emergency! --More--(71%) INTERNATIONAL DIALING With international dialing, the world has been divided into 9 numbering codes. To make an international call, you must dial: International Prefix + Country Code + National # In North America, the international dialing prefix is 011 for station-to- station calls and 01 for operator-serviced calls. IDDD stands for Internation- al Direct Distance Dialing. The country code, which varies from 1 to 3 digis, always has the world numbering zone as the first digit. For example, the country code for the Unit- ed Kingdom is 44, thus it is in world numbering zone 4. Some boards may contain a complete listing of other country codes (check your local white pages), but here are a few: 1 - North America (U.S.A., Canada, etc.) 20 - Egypt 258 - Mozambique 34 - Spain 49 - Germany 52 - Mexico (Southern portion) --More--(80%) 61 - Australia 7 - USSR 81 - Japan 98 - Iran If you call from an area other than North America, the format is generally the same. For example, let's say you want to call the White House from Switzerland. First you would dial 00 (Swiss international dialing prefix), then 1 (United States country code), followed by 202-456-1414 (the national # for the White House). Also, country code 87 is reserved for Maritime Mobile Service, ie calling ships: 871 - Marisat (Atlantic) 872 - Marisat (Pacific) 873 - Marisat (Indian) International Switching: In North America, there are currently 7 #4 ESS's that perform the duty of ISC (International Switching Centers). All international calls dialed from numbering zone 1 will be routed through one of these "gateway cities." They are: 182 - White Plains, New York --More--(90%) 183 - New York, New York 184 - Pittsburgh, Pennsylvania 185 - Orlando, Florida 186 - Oakland, California 187 - Denver, Colorado 188 - New York, New York The 18X series are operator routing codes for overseas access (to be further discussed with Blue Boxes). All international calls use a signaling system called CCITT. It is an international standard for signaling. COMING SOON: In Part IV, we will discuss switching equipment, various operators, CO types, et cetera. References/Acknowledgements: Notes on the Network, AT&T; TAP, room 603, 147 W 42 st., New York, NY 10036; Understanding Telephone Electronics, and many others/TUC, Mulcher ][, Cheshire Catalyst, and many others who have contributed in one way or another to this article.  --More--(99%) {G-Files} Command : Please enter either [file-name], [l], [h], [q], or [?]