Greetings! I have compiled information about the SACs for your edification;
these include 700, 800, and 900.
Most telephone users from the United States are quite familiar with 800
service: A number that they dial and incur NO charge (not even message units
in most areas).
Then there is 900 service, which is what most people perceive as 'value added,'
i.e. you pay more for the information than for the transport of the call.
These vary typically from 35 cents to a few dollars for either a timed service,
or a 'as long as you like' duration-sensitive service. There are two
sub-species of 900 service: AT&T and "everybody else."
Finally, there is 700 service, which many people remember as Alliance
Teleconferencing. This is the third "canonical" SAC. With few limitations,
this SAC is given over to the IEC entirely.
Let's look at these in more detail.
800 Service
~~~~~~~~~~~
800 service is offered by various IECs. Each NXX in the 800 SAC is assigned to
a given carrier, who is responsible for assigning numbers from that block to
customers, and providing 10 digit translation.
The carrier must have Feature Group D presence for originating calls from the
originating exchange (either direct, or through an access tandem).
In the future, when CCIS becomes wide-spread, a query will be made in the
database [Who gets 1-800-985-1234?] and the call will be routed appropriately.
To clarify: Now the carrier is determined by the NNX. In the future, the
carrier will be determined by the entire 7 digits.
A similar situation exists with 900 service. Each carrier can reserve NXXs
from BellCore (the people who among a zillion other tasks are in charge of
handing out prefixes and area codes). They're not cheap! To get the actual
number is free (there are qualifications that I don't deal with), but to get it
'turned on' in a LATA costs you money, depending on:
(1) How many prefixes you're getting,
(2) Whether it's 800 or 900 service; and,
(3) How many Tandems/End Offices are in the LATA.
It requires a discrete amount of labor for EACH office, because EACH routing
table must be modified. However, I will be discussing 900 Service in more
detail later in this file.
When you, as Joe Customer, dial 1-800-222-1234 (made up number, please don't
bother them) it will initiate the following sequence:
1. If you are in an Electronic Office (DMS-100, DMS-200, 1A ESS, 5 ESS)
the 800-222 will be translated to "AT&T" and will search for an
opening in a trunk group marked for 800 origination. Should none be
found, bump to step 3.
2. If you are in a non-electronic office (SxS, XB, and some flavors of
ESS), it will go to the access tandem that your office 'homes' on,
where 800-222 will be translated to "AT&T."
Note: If at this point, the number doesn't have a translation, you
will get a "lose" recording from the CO.
3. Find a trunk in a trunk group marked for 800 origination. Should none
be found, give the customer a recording "Due to network congestion,
your 800 call could not be completed" or die, or whatever. (Depends
on phase of moon, etc.)
4. The end office will the send the following pulse-stream (in MF):
KP + II + 3/10D + ST + KP + 800 222 1234 + ST
Note: This is a simplification; there are some fine points of ANI
spills that are beyond the scope of this file.
II = 2 information digits. Typical values are:
00 normal ANI .. 10 digits follow
01 ONI line ... NPA follows
02 ANI failure ... NPA follows
3/10D = 3 or 10 digits. Either the NPA, or the entire 10 digit
number. KP and ST are control tones.
5. The carrier receives all of this (and probably throws the ANI into the
bit bucket) and translates the 800 number to what's called a PTN, or
Plant Test Number (for example, 617-555-9111). Then, the call is
routed AS IF the customer had dialed that 10 digit number. Of course,
the billing data is marked as an 800 call, so the subscriber receiving
the call pays the appropriate amount.
Of the 800 possible NXXs, 409 are currently assigned. A long-distance carrier
can get one 800 and four 900 numbers just for the paperwork. But to get more
than that, you have to show that you're 70% full now, and demonstrate a real
need for the capacity.
I have included the entire 800-NXX to long-distance carrier translation table.
Note that not every NXX is valid in every area.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Revised 800/OCN Translation Table
Effective October 10, 1988
Notes
~~~~~
*1 -- Released For Future Assignment
*2 -- These NXX codes are generally reserved for test applications; They
may be reserved for Access Tandem testing from an End Office.
Note also: The following NXXs are dedicated for RCCP (Radio Common Carrier
Paging) under the discretion of the local exchange carrier:
OCN Reference List
~~~~~~~~~~~~~~~~~~
ADG - Advantage Network, Inc. AGN - AMRIGON
ALG - Allnet Communication Services AMM - Access Long Distance
AAM - ALASCOM ARE - American Express TRS
ARZ - AmeriCall Corporation (Calif.) ATC - Action Telecom Co.
ATX - AT&T BML - Phone America
BUR - Burlington Tel. CAB - Hedges Communications
CAN - Telcom Canada CNO - COMTEL of New Orleans
CQU - ConQuest Comm. Corp CSY - COM Systems
CUX - Compu-Tel Inc. CYT - ClayDesta Communications
DCT - Direct Communications, Inc. DLT - Delta Communications, Inc.
EDS - Electronic Data Systems Corp. ETS - Eastern Telephone Systems, Inc.
EXF - Execulines of Florida, Inc. FDG - First Digital Network
FDN - Florida Digital Network FDT - Friend Technologies
FST - First Data Resources GCN - General Communications, Inc.
GTS - Telenet Comm. Corp. HNI - Houston Network, Inc.
ITT - United States Transmission System LDD - LDDS-II, Inc.
LDL - Long Distance for Less LGT - LITEL
LNS - Lintel Systems LSI - Long Distance Savers
LTQ - Long Distance for Less MAL - MIDAMERICAN
MCI - MCI Telecommunications Corp. MDE - Meade Associates
MEC - Mercury, Inc. MIC - Microtel, Inc.
MIT - Midco Communications MTD - Metromedia Long Distance
NLD - National Data Corp. NTK - Network Telemanagement Svcs.
NTS - NTS Communications ONC - OMNICALL, Inc.
ONE - One Call Communications, Inc. PHE - Phone Mail, Inc.
PLG - Pilgrim Telephone Co. PRO - PROTO-COL
RBW - R-Comm RTC - RCI Corporation
SAN - Satelco SCH - Schneider Communications
SDY - TELVUE Corp. SIR - Southern Interexchange Services
SLS - Southland Systems, Inc. SNH - Sunshine Telephone Co.
SNT - SouthernNet, Inc. SOC - State of California
TBQ - Telecable Corp. TDD - Teleconnect
TDX - Cable & Wireless Comm. TED - TeleDial America
TEM - Telesystems, Inc. TEN - Telesphere Network, Inc.
TET - Teltec Savings Communications Co TGN - Telemanagement Consult't Corp.
THA - Touch America TID - TMC South Central Indiana
TKC - TK Communications, Inc. TLS - TELE-SAV
TMU - Tel-America, Inc. TNO - ATC Cignal Communications
TOM - TMC of Montgomery TOR - TMC of Orlando
TSF - SOUTH-TEL TSH - Tel-Share
TTH - Tele Tech, Inc. TTU - Total-Tel USA
TXN - Tex-Net USL - U.S. Link Long Distance
UTC - U.S. Telcom, Inc. (U.S. Sprint) VOA - Valu-Line
VST - STAR-LINE WES - Westel
WUT - Western Union Telegraph Co.
NOTE: Where local telcos, such as Illinois Bell, offer 800 service, they
purchase blocks of numbers from AT&T on prefixes assigned to AT&T. They
are free to purchase blocks of numbers from any carrier of their choice
however.
This list also applies to the 900/OCN Translation Table (presented later
in this file).
900 Service
~~~~~~~~~~~
As I mentioned earlier there are two flavors of 900 service, AT&T and
"everybody else." Everybody else is handled exactly as the 800 service above,
except the IEC will probably use the ANI information to send you a bill
(either directly, or through your BOC, each situation governed by applicable
tariffs and contractual arrangements between the IEC and the BOC).
AT&T 900 is a curious monster indeed. It was designed as a "mass termination"
service. When you dial a 900 by AT&T (such as the "hear space shuttle
mission audio" number) you get routed to one of twelve "nodes" strewn
throughout the country. These nodes are each capable of terminating 9,000
calls >PER SECOND<. There are several options available where the customer
and/or the IP pay for all/part of the call. The big difference between 800 and
AT&T 900 is >NOT< "who pays for the call" (there are free 900 numbers), but
"how many people can it handle at once." The IP is responsible for providing
program audio. AT&T is prohibited from providing audio-program services (i.e.
tape recorded messages). As with any rule, there are exceptions to these as
well.
Revised 900/OCN Translation Table
Effective October 10, 1988
Please note that this differs from the 800 table, because much fewer of the 900
NXXs are assigned.
NXX OCN NXX OCN NXX OCN NXX OCN NXX OCN
200 ATX 202 Ameritech 210 ATX 220 ATX 221 TDX
222 ONC 223 TDX 225 Pac. Bell 226 MCI 233 TDX
234 TEN 240 U.S. West 248 Ameritech 250 ATX 258 TEN
254 TTU 255 SNT 260 ATX 264 ADG 266 CSY
272 Bell Atl. 273 CAN 275 ITT 280 Ameritech 282 LGT
283 Pac. Bell 288 GTE N.west 297 CAN 300 ATX 301 Ameritech
302 Ameritech 303 Pac. Bell 321 TEN 322 TDX 327 ETS
328 ATX 331 TET 332 PLG 333 U.S. West 335 Bell Atl.
342 ATX 344 ATX 345 ALN 346 United Tel. 350 ATX
364 GTE N.West 366 ONC 369 TEN 370 ATX 377 GTS
386 United Tel. 388 SNT 399 ARZ 400 ATX 407 ATX
410 ATX 420 ATX 422 ALN 426 PLG 428 Ameritech
430 U.S. West 444 ONC 445 PHE 446 MCI 450 Ameritech
451 CAN 456 TEN 463 United Tel. 478 AAM 479 ARZ
480 ATX 483 GTE Midwest 488 ONC 490 U.S. West 500 ATX
505 Pac. Bell 520 ATX 529 MIT 536 BUR 540 ALN
543 ALN 545 GTE Calif. 550 ALN 555 ATX 567 ALN
580 U.S. West 590 ATX 595 CAN 600 ATX 620 Ameritech
624 Pac. Bell 626 CSY 628 Ameritech 630 CAN 633 MIT
639 PLG 643 CAN 645 CAN 650 ATX 654 TEN
656 SNT 660 ATX 661 United Tel. 663 MDE 665 ALN
666 ONC 670 CAN 677 CAN 678 MCI 680 ATX
686 LTG 690 CAN 698 NY Tel. 699 PLG 701 Bell Atl.
710 TGN 720 ATX 722 Pac. Bell 724 RTC 725 SNT
727 GTE Calif. 730 ATX 739 CSY 740 ATX 741 TEN
746 ITT 750 CAN 753 ALN 765 ALN 773 ATX
777 Pac. Bell 778 Ameritech 780 Ameritech 786 ATX 790 CAN
792 CAN 801 Bell Atl. 820 ATX 830 CAN 843 Pac. Bell
844 Pac. Bell 847 United Tel. 850 ATX 860 ATX 866 AAM
870 CAN 872 TEN 887 ETS 888 CIS 900 TDX
901 Bell Atl. 903 ATX 909 ATX 924 Ameritech 932 ATX
948 ARZ 949 MIC 963 TEN 970 MIC 971 MIC
972 MIC 973 MIC 974 ALN 975 ALN 976 ATX
988 MCI 990 MCI 991 ALG 993 SNT 999 TEN
700 Service
~~~~~~~~~~~
The last SAC we'll deal with is 700. I've seen ads on late-night television
for Group Access Bridging service (GAB) under 700 numbers, with an elephantine
dialing sequence. The one that comes to mind is 10041-1-700-777-7777. If you
were to dial 1-700-555-4141 you will hear a recording announcing your
Equal-Access carrier. (Some carriers ignore the last four digits, and any
700-555 number will give the announcement).
This is signalled the same as 800 service, and may or may not be billed
ENTIRELY at the discretion of the IEC. In New York, under PSC tariff, you can
order 900 and/or 700 blocking as well as 976, 970, 550, and 540 blocking in
various combinations.
What in ONE carrier might be a customer service hotline (Dial 1-700-I AM LOST)
might for another be a revenue product. There is LITTLE standardization of 700
usage from IEC to IEC.
The one last dialing pattern that is worth mentioning is what's called, "cut
through dialing." Try dialing 10220. If Western Union comes to your
town, you'll get a FG-A style dial tone. Presumably if you had a Western
Union "Calling Card" you could dial a call.
Glossary
~~~~~~~~
ANI - Automatic Number Identification. An MF sequence that identifies your
line for toll billing information. Often confused with ANAC (Automatic
Number Announcement Circuit) which reads your number back in a
synthesized voice.
BOC - Bell Operating Company. An often misused term that in general usage
means, "Your local exchange carrier." Since most of the telephones in
the country are served by what used to be the Bell system, we tend to use
the term. The proper term in this case, however IS "Exchange Carrier
[EC]" They provide service within your LATA.
FG-A - Feature Group A. Line Side termination for Long Distance carriers. The
old 555-1234 for Widget Telephone Company then dial an access code and
the number style dialing is called FG-A.
FG-B - Feature Group B. Trunk Side termination for Long Distance carriers.
(aka ENFIA B). 950 service. This is LATA wide service, and doesn't
cost the customer message units. ANI is only provided when the trunks
terminate in the End Office (as opposed to an access tandem).
FG-D - Feature Group D. Trunk Side termination. Provides 10xxx dialing, 1+
pre-subscription dialing, and Equal Access 800/900 service. Only
available in electronic offices and some 5XB offices (through a beastie
called an Adjunct Frame.)
GAB - Group Audio Bridging. Where several people call the same number, to talk
to other people calling the same number. "Party" or "Chat" lines.
IEC - Inter-Exchange Carrier. Someone who actually carries calls from place to
place. AT&T, Sprint, MCI are all IECs.
IP - Information Provider. Someone who sells a value-added service over the
telephone. Where you pay for the INFORMATION you're receiving, as well as
the cost of TRANSPORT of the call.
NXX - Notation convention for what used to be called a "prefix". N represents
the digits 2 through 9, and X represents the digits 0 through 9. There
are 800 valid NXX combinations, but some are reserved for local use.
(411 for Directory, 611 for Repair Bureau, 911 for emergency, etc.)
ONI - Operator Number Identification. In areas with some styles of party-line
service, the CO cannot tell who you are, and the operator will come on
and say, "What number are you calling from?". You can lie, they have to
trust you. They MAY know which PREFIX you're coming from, though.
PTN - Plant Test Number. A regular 10 digit number assigned with your inward
WATS line. This may NOT be a 'dialable' number from the local CO. (A
friend has a WATS line in Amherst, MA [413-549,
dial the PTN locally, but you can if you come in on a toll trunk.)
SAC - Special Area Code. Bellcore speak for area codes that aren't really
places, but classes of service.
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