Phone Systems Tutorial by The Jolly Roger

To start off, 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 , ie, area code

B) a 7 digit telephone # consisting of a 3 digit Central Office

(CO) code plus a 4 digit station #


These 10 digits are called the network address or destination

code. It is in the format of:

Area Code Telephone #

--------- -----------




Where: N = a digit from 2 to 9

* = the digit 0 or 1

X = a digit from 0 to 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 - WATS

810 - TWX (USA)

900 - DIAL-IT Services

910 - TWX (USA)


The other area codes never cross state lines, therefore each state

must have at least one exclusive NPA code. When a community is

split by a state line, the CO #'s are often interchangeable (ie,

you can dial the same number from two different area codes).


TWX (Telex II) consists of 5 teletype-writer area codes. They are

owned by Western Union. These SAC's may only be reached via other

TWX machines. These run at 110 baud (last I checked! They are most

likely faster now!). Besides 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) 279-5956. The

answerback for this service is "WU FYI MAWA".


If you don't want to but a TWX machine, you can still send TWX

messages using Easylink [800/325-4112]. However you are gonna have

to hack your way onto this one!




700 is currently used by AT&T as a call forwarding service. It is

targeted towards salesmen on the run. To understand how this

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 who royally screwed up an important COSMOS

system. Let's say that Joe's 700 # is (700) 382-5968. Everytime

Joe goes to a new hotel (or most likely SLEAZY MOTEL), he dials a

special 700 #, enters a code, and the number where he is staying.

Now, if his boss received some important info, all he would do is

dial (700) 382-5968 and it would ring wherever Joe last progammed

it to. Neat, huh?




This SAC is one of my favourites since it allows for toll free

calls. INWARD WATS (INWATS), or 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 the state where the call is terminated

(that is why most companies have one 800 number for the countery

and then another one for their 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 1 state)

always have a 2 as the last digit in the exchange (ie, 800-NX2-

XXXX). The NXX on 800 #'s represent the area where the business is

located. For example, a # beginning with 800-431 would terminate

at a NY 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 will try the next #, etc. You must have a minimum

of 2 lines for 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 to the next

available port, etc. INWATS customers are billed by the number of

hours of calls made to their #.


OUTWATS (OUTWARD WATS): OUTWATS are for making outgoing calls

only. Largecompanies use OUTWATS since they receive bulk-rate

discounts. Since OUTWATS numbers cannot have incoming calls, they

are in the format of:


(800) *XXX-XXXX


Where * is the digit 0 or 1 (or it may even be designated by a

letter) which cannot be dialed unless you box the call. The *XX

identifies the type of service and the areas that the company can









This DIAL-IT SAC is a nationwide dial-it service. It is use for

taking television polls and other stuff. The first minute

currently costs an outrageous 50-85 cents and each additional

minute costs 35-85 cents. Hell takes in a lot of revenue this way!


Dial (900) 555-1212 to find out what is currently on this service.





These identify the switching office where the call is to be

routed. The following CO codes are reserved nationwide:


555 - directory assistance

844 - time. These are now 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 & ringback #'s are regarded as plant test

and are thus reserved. These numbers vary from area to area.


You cannot dial a 0 or 1 as the first digit of the exchange code

(unless using a blue box!). This is due to the fact that these

exchanges (000-199) contains all sorts of interesting shit such as

conference #'s, operators, test #'s, etc.




Here are the services that are currently used by the 950 exchange:


1000 - SPC

1022 - MCI Execunet

1033 - US Telephone

1044 - Allnet

1066 - Lexitel

1088 - SBS Skyline


These SCC's (Specialized Common Carriers) are free from fortress

phones! Also, the 950 exchange will probably be phased out with

the introduction of Equal Access


Plant Tests:


These include ANI, Ringback, and other various tests.




Dial 976-1000 to see what is currently on the service. Also, many

bbs's have listings of these numbers.


N11 codes:


Bell is trying to phase out some of these, but they still exist in

most areas.


011 - international dialing prefix

211 - coin refund operator

411 - directory assistance

611 - repair service

811 - business office



International Dialing



With International Dialing, the world has been divided into 9

numbering zones. To make an international call, you must first

dial: International Prefix + Country code + National #


In North America, the international dialing prefix is 011 for

station-to-station calls. If you can dial International #'s

directly in your area then you have International Direct Distance

Dialing (IDDD).


The country code, which varies from 1 to 3 digits, always has the

world numbering zone as the first digit. For example, the country

code for the United Kingdom is 44, thus it is in world numbering

zone 4. Some boards may contain a complete listing of other

country codes, but here I give you a few:


1 - North America (US, Canada, etc.)

20 - Egypt

258 - Mozambique

34 - Spain

49 - Germany

52 - Mexico (southern portion)

7 - USSR

81 - Japan

98 - Iran (call & hassle those bastards!)


If you call from an area other than North America, the format is

generally the same. For example, let's say that you wanted to call

the White House from Switzerland to tell the prez that his

numbered bank account is overdrawn (it happens, you know! ha ha).

First you would dial 00 (the SWISS international dialing refix),

then 1 (the US country code), followed by 202-456-1414 (the

national # for the White House. Just ask for Georgy and give him

the bad news!)


Also, country code 87 is reserved for Maritime mobile service, ie,

calling ships:


871 - Marisat (Atlantic)

871 - Marisat (Pacific)

872 - Marisat (Indian)


International Switching:



In North America there are currently 7 no. 4 ESS's that perform

the duty of ISC (Inter-nation Switching Centers). All

international calls dialed from numbering zone 1 will be routed

through one of these "gateway cities". They are:


182 - White Plains, NY

183 - New York, NY

184 - Pittsburgh, PA

185 - Orlando, Fl

186 - Oakland, CA

187 - Denver, CO

188 - New York, NY


The 18X series are operator routing codes for overseas access (to

be furthur discussed with blue boxes). All international calls use

a signaling service called CCITT.It is an international standard

for signaling.


Ok.. there you go for now! If you wanna read more about this, read

part two which is the next file #36 in the Jolly Roger's cookbook!