North American Area Codes-NZDF

North American Area Codes

North American Area Codes are a numbering plan (called NANP, North American Numbering Plan) for the public switched telephone network in the United States and its territories , Canada, Bermuda, and many Caribbean nations, including Anguilla, Antigua & Barbuda, Bahamas, Barbados, British Virgin Islands, Cayman Islands, Dominica, Dominican Republic, Grenada, Jamaica, Montserrat, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, and Turks & Caicos. NANP numbers are ten digits in length, and they are in the format: NXX-NXX-XXXX, where N is any digit 2-9 and X is any digit 0-9. The first three digits are called the numbering plan area (NPA) code, often called simply the area code. The second three digits are called the central office code or prefix. The final four digits are called the telephone line number. In May of 2001 there were 344 area codes in North America. For an up-to-date collection, see www.nanpa.com. Here are two lists, one numerically by area code and one alphabetically by area:

North American Area Codes By Number

201	New Jersey
202	District of Columbia
203	Connecticut
204	Manitoba
205	Alabama
206	Washington
207	Maine
208	Idaho
209	California
210	Texas
211	Social Services
212	New York
213	California
214	Texas
215	Pennsylvania
216	Ohio
217	Illinois
218	Minnesota
219	Indiana
224	Illinois
225	Louisiana
228	Mississippi
240	Maryland
242	Bahamas
246	Barbados
248	Michigan
250	British Columbia
252	North Carolina
253	Washington
254	Texas
256	Alabama
264	Anguilla
267	Pennsylvania
268	Antigua/Barbuda
270	Kentucky
281	Texas
284	British Virgin Islands
301	Maryland
302	Delaware
303	Colorado
304	West Virginia
305	Florida
306	Saskatchewan
307	Wyoming
308	Nebraska
309	Illinois
310	California
311	Non-Emergency Access
312	Illinois
313	Michigan
314	Missouri
315	New York
316	Kansas
317	Indiana
318	Louisiana
319	Iowa
320	Minnesota
323	California
330	Ohio
334	Alabama
336	North Carolina
340	US Virgin Islands
345	Cayman Islands
352	Florida
360	Washington
401	Rhode Island
402	Nebraska
403	Alberta
404	Georgia
405	Oklahoma
406	Montana
407	Florida
408	California
409	Texas
410	Maryland
411	Local Directory Assistance
412	Pennsylvania
413	Massachusetts
414	Wisconsin
415	California
416	Ontario
417	Missouri
418	Quebec
419	Ohio
423	Tennessee
424	California
425	Washington
435	Utah
440	Ohio
441	Bermuda
443	Maryland
450	Quebec
456	Inbound International
469	Texas
473	Grenada
484	Pennsylvania
500	Personal Communication Services
501	Arkansas
502	Kentucky
503	Oregon
504	Louisiana
505	New Mexico
506	New Brunswick
507	Minnesota
508	Massachusetts
509	Washington
510	California
511	Road Conditions
512	Texas
513	Ohio
514	Quebec
515	Iowa
516	New York
517	Michigan
518	New York
519	Ontario
520	Arizona
530	California
540	Virginia
541	Oregon
559	California
561	Florida
562	California
570	Pennsylvania
573	Missouri
580	Oklahoma
600	Canada (Services)
601	Mississippi
602	Arizona
603	New Hampshire
604	British Columbia
605	South Dakota
606	Kentucky
607	New York
608	Wisconsin
609	New Jersey
610	Pennsylvania
611	Repair Service
612	Minnesota
613	Ontario
614	Ohio
615	Tennessee
616	Michigan
617	Massachusetts
618	Illinois
619	California
626	California
630	Illinois
649	Turks & Caicos Islands
650	California
651	Minnesota
660	Missouri
661	California
664	Montserrat
670	CNMI
671	Guam
678	Georgia
700	IC Services
701	North Dakota
702	Nevada
703	Virginia
704	North Carolina
705	Ontario
706	Georgia
707	California
708	Illinois
709	Newfoundland
710	U.S. Government
711	TRS Access
712	Iowa
713	Texas
714	California
715	Wisconsin
716	New York
717	Pennsylvania
718	New York
719	Colorado
720	Colorado
724	Pennsylvania
727	Florida
732	New Jersey
734	Michigan
740	Ohio
757	Virginia
758	St. Lucia
760	California
765	Indiana
767	Dominica
770	Georgia
773	Illinois
775	Nevada
780	for Northern Alberta, Canada
781	Massachusetts
784	St. Vincent & Grenada
785	Kansas
786	Florida
787	Puerto Rico
800	Inbound toll-free calling
801	Utah
802	Vermont
803	South Carolina
804	Virginia
805	California
806	Texas
807	Ontario
808	Hawaii
809	Caribbean Islands
810	Michigan
811	Business Office
812	Indiana
813	Florida
814	Pennsylvania
815	Illinois
816	Missouri
817	Texas
818	California
819	Quebec
828	North Carolina
830	Texas
831	California
832	Texas
843	South Carolina
847	Illinois
850	Florida
855	Inbound toll-free calling
858	California
860	Connecticut
864	South Carolina
866	Inbound toll-free calling
867	for NorthWest, Yukon and Nunavut Territories
868	Trinidad and Tobago
869	St. Kitts & Nevis
870	Arkansas
876	Jamaica
877	800 Service (also 888)
880	PAID-800 Service
881	PAID-888 Service
882	PAID-877 Service
888	800 Service (also 877)
900	900 Service
901	Tennessee
902	Nova Scotia
903	Texas
904	Florida
905	Ontario
906	Michigan
907	Alaska
908	New Jersey
909	California
910	North Carolina
911	Emergency
912	Georgia
913	Kansas
914	New York
915	Texas
916	California
917	New York
918	Oklahoma
919	North Carolina
920	Wisconsin
925	California
931	Tennessee
935	California
937	Ohio
940	Texas
941	Florida
949	California
954	Florida
956	Texas
970	Colorado
972	Texas
973	New Jersey
978	Massachusetts

North American Area Codes By Place

800	800 Service
888	800 Service Expansion
877	888 Service Expansion
900	900 Service
205	Alabama
256	Alabama
334	Alabama
907	Alaska
403	Alberta
780	Alberta
264	Anguilla
268	Antigua/Barbuda
520	Arizona
602	Arizona
501	Arkansas
870	Arkansas
242	Bahamas
246	Barbados
441	Bermuda
250	British Columbia
604	British Columbia
284	British Virgin Islands
811	Business Office
209	California
213	California
310	California
323	California
408	California
415	California
424	California
510	California
530	California
559	California
562	California
619	California
626	California
650	California
661	California
707	California
714	California
760	California
805	California
818	California
831	California
858	California
909	California
916	California
925	California
935	California
949	California
600	Canada (Services)
809	aribbean Islands
345	Cayman Islands
670	CNMI
303	Colorado
719	Colorado
720	Colorado
970	Colorado
203	Connecticut
860	Connecticut
302	Delaware
202	Dist. of Columbia
767	Dominica
911	Emergency
305	Florida
352	Florida
407	Florida
561	Florida
727	Florida
786	Florida
813	Florida
850	Florida
904	Florida
941	Florida
954	Florida
404	Georgia
678	Georgia
706	Georgia
770	Georgia
912	Georgia
473	Grenada
671	Guam
808	Hawaii
700	IC Services
208	Idaho
217	Illinois
224	Illinois
309	Illinois
312	Illinois
618	Illinois
630	Illinois
708	Illinois
773	Illinois
815	Illinois
847	Illinois
456	Inbound International
219	Indiana
317	Indiana
765	Indiana
812	Indiana
319	Iowa
515	Iowa
712	Iowa
876	Jamaica
316	Kansas
785	Kansas
913	Kansas
270	Kentucky
502	Kentucky
606	Kentucky
411	Local Directory Assistance
225	Louisiana
318	Louisiana
504	Louisiana
207	Maine
204	Manitoba
240	Maryland
301	Maryland
410	Maryland
443	Maryland
413	Massachusetts
508	Massachusetts
617	Massachusetts
781	Massachusetts
978	Massachusetts
231	Michigan
248	Michigan
313	Michigan
517	Michigan
616	Michigan
734	Michigan
810	Michigan
906	Michigan
218	Minnesota
320	Minnesota
507	Minnesota
612	Minnesota
651	Minnesota
228	Mississippi
601	Mississippi
314	Missouri
417	Missouri
573	Missouri
660	Missouri
816	Missouri
406	Montana
664	Montserrat
308	Nebraska
402	Nebraska
702	Nevada
775	Nevada
506	New Brunswick
603	New Hampshire
201	New Jersey
609	New Jersey
732	New Jersey
908	New Jersey
973	New Jersey
505	New Mexico
212	New York
315	New York
516	New York
518	New York
607	New York
716	New York
718	New York
914	New York
917	New York
709	Newfoundland
311	Non-Emergency Access
252	North Carolina
336	North Carolina
704	North Carolina
828	North Carolina
910	North Carolina
919	North Carolina
701	North Dakota
902	Nova Scotia
216	Ohio
330	Ohio
419	Ohio
440	Ohio
513	Ohio
614	Ohio
740	Ohio
937	Ohio
405	Oklahoma
580	Oklahoma
918	Oklahoma
416	Ontario
519	Ontario
613	Ontario
647	Geographic Relief Code
705	Ontario
807	Ontario
905	Ontario
503	Oregon
541	Oregon
880	PAID-800 Service
882	PAID-877 Service
881	PAID-888 Service
215	Pennsylvania
267	Pennsylvania
412	Pennsylvania
484	Pennsylvania
570	Pennsylvania
610	Pennsylvania
717	Pennsylvania
724	Pennsylvania
814	Pennsylvania
500	Personal Communication Services
787	Puerto Rico
418	Quebec
450	Quebec
514	Quebec
819	Quebec
611	Repair Service
401	Rhode Island
306	Saskatchewan
803	South Carolina
843	South Carolina
864	South Carolina
605	South Dakota
869	St. Kitts & Nevis
758	St. Lucia
784	St. Vincent & Grenada
423	Tennessee
615	Tennessee
901	Tennessee
931	Tennessee
210	Texas
214	Texas
254	Texas
281	Texas
409	Texas
469	Texas
512	Texas
713	Texas
806	Texas
817	Texas
830	Texas
832	Texas
903	Texas
915	Texas
940	Texas
956	Texas
972	Texas
868	Trinidad and Tobago
711	TRS Access
649	Turks & Caicos Islands
710	U.S. Government
340	US Virgin Islands
435	Utah
801	Utah
802	Vermont
540	Virginia
703	Virginia
757	Virginia
804	Virginia
206	Washington
253	Washington
360	Washington
425	Washington
509	Washington
304	West Virginia
414	Wisconsin
608	Wisconsin
715	Wisconsin
920	Wisconsin
307	Wyoming
867	Yukon & NW Territories.

North American Cellular Network

A Craig McCaw idea to join together a bunch of cellular phone companies providers who would provide a painless, simple way for someone making or receiving a cellular call in their territory. Previously, traveling cellular users ” what the industry calls "roamers" ” were forced to pay heavy charges for calling from the territory of a cellular company not theirs. And roamers were, in effect, incommunicado from incoming calls. It was impossible to call someone on a cellular phone if they were not in the own territory and you didn't know where they were. Craig McCaw was the founder of McCaw Communications, a large cellular phone company, now owned by AT&T.

North American Directory Forum

NADF. An association of electronic mail providers who are figuring standards and ways of sending mail between their subscribers.

North American ISDN Users Forum

NIUF. Here is the complete explanation of this important group , as excerpted from their brochure: The barriers to the widespread use of ISDN nationally and internationally is difficult because the technology is complex and developing rapidly . One underlying problem is the lack of standard implementations of ISDN applications. ISDN standards are currently developed by the International Telecommunications Union (ITU-T) and by accredited standards committee T-1 under the umbrella of the American National Standards Institute (ANSI). But standards designed to meet many requirements offer multiple options which are open to diverse interpretations. As a result, services and products produced by different manufacturers are incompatible.

To solve this problem, NIST (National Institute of Standards and Technology) collaborated with industry in 1988 to establish the North American ISDN Users' Forum (NIUF). NIST's Computer Systems Laboratory (CSL) serves as chair of the forum and hosts the NIUF Secretariat under the terms of a cooperative Research and Development Agreement (CRADA) established with industry in 1991. Through support of the forum, CSL advances new uses of computer and telecommunications technology in government and industry. The objectives of the NIUF are "to provide users the opportunity to influence developing ISDN technology to reflect their needs; to identify ISDN applications, develop implementation requirements, and facilitate their timely , harmonized, and interoperable introduction; and to solicit user , product provider, and service provider participation in the process." www.niuf.nist.gov.

North American Numbering Plan

NANP. The method of identifying telephone trunks in the public network of North America, called World Numbering Zone 1 by the ITU-T. The Plan has three ways of identifying phone numbers in North America ” a three digit area code, a three digit exchange or central office code and four digit subscriber code. Other countries have much more complicated numbering schemes. There are some countries, for example, where the length of the area code actually exceeds the subscriber code. There are many countries where there is no consistency in the length of phone numbers. Some are nine-digit. Some are 12-digit, etc. All these varying number lengths may be within 100 miles of each other.

Under the NAN P format prior to January 1, 1995, the second digit of the area code was always a one or a zero. With this system, approximately one billion telephone numbers, 152 area code combinations and 640 prefixes were available. Numbers started to run out as a result of increased use of fax, modem and cellular lines. With the new Numbering Plan introduced on January 1, 1995, the area code can be any combination of three digits. This will allow more than 6 billion telephone numbers and 792 area code combinations. See NANC and NANP.

North American Telecommunications Association

NATA. Now known as the MultiMedia Telecommunications Association MMTA. The national trade association for companies providing customer premise telephone equipment. NATA represents the interests of the industry before the Congress, the FCC and in court actions. It also does market research. www.MMTA.org.

North Dakota

In North Dakota, it is legal to shoot an Indian on horseback, provided you are in a covered wagon.

NOS

A network operating system is software that runs a network (as if that wasn't self- evident). It typically runs in a file server and controls access to shared and non-shared files and allows users to communicate with each other and to gain access to shared facilities, like printers, data storage devices, scanners , routers, bridges, and of course. It's also the software that communicates with the LAN hardware (also called network interface card) in each device (PC, printer, file server, gateway, router, etc.) attached to the network. What makes a network operating system (NOS) different from today's computer operating system (OS)? Today, the answer is: very little. Virtually all computers now include a network operating system. However, all operating systems were not always network-aware, and just because an OS was network-aware did not necessarily qualify it as a Network OS. The first true NOS products to emerge included Novell NetWare and Banyan Vines. These network operating systems were engineered to provide network-specific functionality such as shared access to large (and expensive) disk drives , printers, multi-user applications, and provided additional security that most mere operating systems lacked. Such network operating systems were either not intended to support, or were incapable of supporting, end- user applications. Most were/are dedicated to providing network services, hence the term , "dedicated server". By this definition, since Vines is defunct , NetWare is the only remaining NOS. Some may also insist that many versions of Windows, Unix/Linux, as well as the Mac OS, are in fact network operating systems. While all current releases of these operating systems are certainly network-aware, they are by no means dedicated to supporting network services only. Of these, only Microsoft offers a server-specific release of its Windows operating system(s), however, Windows 2000 Server and Advanced Server share the same operating system kernel as the client workstation version, Windows 2000 Professional. The server versions augment this basic OS with additional networking capabilities and server- related applications and utilities. The new Windows XP Home and XP Professional operating systems are also network-aware, however there is currently no server version of Windows XP.

Nose

The human nose cleans, warms, and humidifies over 500 cubic feet of air every day.

Not!

An expression of disagreement with a previous statement.

NOT Function

See Digital Inverter.

Not Statement

A "not" operator is one of three fundamental logic operations that underlie all computer calculations. The other two operations are "and" and "or". The "and" operator compares whether two statements are both true. The "or" operator determines if at least one statement is true. In the binary language of 1's and 0's used by computers, a "not" operator converts a "0" (the equivalent of "false") into a "1" ("true"). It also works the other way, changing a "1" into a "0." Computer calculations are all reduced to combinations of "and," "or" and "not" operators.

NoTAR

No TelecomAction Required.

Notch

An out-of-phase impulse causing spontaneous dip in voltage. This is an under-voltage impulse, similar to a spike, but of reverse polarity to the instantaneous value of the AC sine wave. A notch normally is associated with the power company removing a generator from the power grid. See Notched Noise.

Notch Filter

A filter that blocks or passes a specific band of frequencies. The filters are: lowpass/block, high pass/block, notch pass/block. If the filter is set in a series with a circuit, the desired frequencies pass down the line. If it's passed to ground, the desired frequencies are sent to ground. They can't get through the circuit.

Notched Noise

Noise in which a narrow band of frequencies has been removed. Normally used for testing devices or circuits.

Notebook

A laptop computer that weighs approximately five to seven pounds . Sub- notebooks clearly weigh less.

Notes on The Network

A famous book explaining how the North American public switched network works. It's now called BOC Notes on the LEC Networks.

NOTHS

Network Operations Trouble Handling System.

Notwork

A network in its nonworking state.

Notice of Inquiry

NOI. A Federal Communications Commission term, a Notice of Inquiry (NOI) is adopted by the Commissioners primarily for fact gathering, a way to seek comments from the public or industry on a specific issue. The NOI also states where and when comments may be submitted, where and when you can review comments others have made, and how to respond to those comments. After reviewing comments, the FCC may issue a Notice of Proposed Rulemaking or it may release a Report & Order (R&O) explaining what action ” or non-action ” is taken.

Novell

Novell is the reincarnation of NDSI, a computer firm that almost went under in the early 1980s. The then nearly 60-year-old Ray Noorda, who had 20 years of experience in systems automation with General Electric was called in to help NDSI prepare for a trade show. He spotted it had some potentially interesting technology, and bought the ailing company in 1983. He sold most of his holdings in the 1990s. Novell was one of the earliest pioneers in PC networking. At one stage everyone who had a network of PCs ran Novell's software, called NetWare. Microsoft seriously impacted Novell's business by simply including networking software in its various incarnations of Windows.

Novell Directory Services

See NDS.

Novell IPX

See IPX.

Novell NLSP

Novell NetWare Link Services Protocol. A link state protocol under development by Novell to improve performance of IPX traffic in large internetworks.

Novell SAP

Novell Service Advertisement Protocol. See SAP.

Novell Telephony Services

See Telephony Services.

NP

See Number Portability.

NP3

Non-published telephone number service.

NPA

1. In IBM language, it means Network Performance Analyzer, a product for network tuning, determining performance, degradation and determining the affect of network growth.

2. Numbering Plan Area. A fancy way of saying Area Codes. There are well over 200 area codes in the United States, Canada, Bermuda, the Caribbean, Northwestern Mexico, Alaska and Hawaii. Within any of these area codes, no two telephone lines may have the same seven digit phone number. The middle number has been either "1" or "0" creating "N 1/0 x" codes. The number of codes available on this basis were nearing depletion. Bellcore (now Telcordia Technologies) then modified the plan to obtain more area codes by changing the area codes numbering scheme to NXX like the central office numbering scheme. Switching systems in the national network differentiate between the central office and area codes by recognizing the subscriber always dials 1+ or 0+ preceding an area code when direct dialing such long distance calls. The responsibility for numbering plan administration (NPA) was shifted in 1997 from Bellcore to Lockheed Martin, as Bellcore no longer was considered to be an impartial party.

Here are the special, unassigned and reserved NPAs:

200 Reserved for special services

211 Assigned to local operators

300 Assigned to special services

311 Reserved for special local services

400 Reserved for special services

500 Reserved for special services

511 Reserved for special local services

600 Reserved for special services

700 Assigned special access code for interLATA carriers / resellers

711 Reserved for special local services

See NNX and North American Area Codes.

NPA Code

A unique 3-digit code in the N 0/1X series that identifies and NPA (Numbering Plan Area). An NPA code is the first three digits of the destination code for all inter-NPA toll calls. See NPA.

NPA/NXX

The first six digits of a North American telephone number; the area code and exchange.

NPAC

Number Portability Administration (also called Access) Center. Regional centers which will be developed to assist in the implementation of Local Number Portability (LNP). The NPAC will interact with the LSOAs (Local Service Order Administration) systems of all carriers in order to effect the transportation of the end user's telephone number from the legacy Local Exchange Carrier (LEC) to the new LEC of choice. LNP effectively decouples customer identification number (Directory Number) from Network Routing Address (Location Routing Number or LRN). The NPACs serve to synchronize the numbering databases, and to coordinate the porting process. As orders are placed to change the serving LEC, the OSSs (Operations Support Systems) of the victorious LEC communicate that request to its Local Service Order Administration (LSOA) system, which passes the request to the NPAC. The NPAC notifies the legacy carrier's LSOA of the request for purposes of confirmation. Once confirmed and ported, the NPAC passes relevant data to to all carrier LSOAs in its region, which, in turn , pass that information to its LSMSs (Local Service Management Systems), which pass the change to the LSOAs, which pass it on to the appropriate OSSs. There are seven NPACs designated in the U.S., with Lockheed Martin serving all seven regions. Originally, Perot Systems served three regions , but it pulled out. Now Lockheed Martin runs all seven. There is a single NPAC in Canada. See also LNP.

NPC

1. Network Processing Card.

2. Network Parameter Control: Network Parameter Control is defined as the set of actions taken by the network to monitor and control traffic from the NNI. Its main purpose is to protect network resources from malicious as well as unintentional misbehavior which can affect the QoS of other already established connections by detecting violations of negotiated parameters and taking appropriate actions. Refer to UPC.

NP&D

Network Planning and Design.

NPD

1. See Network Protection Device.

2. Network Performance Display.

NPDA

Network Problem Determination Application. A program which allows for the monitoring of an entire network from a single location, collection of statistics, and isolation of communication faults. An IBM term. See Netview.

NPDU

Network Protocol Data Unit.

NPI

1. Network Product Implementation.

2. A term used by computer support personnel to calm clueless users, it stands for Not Plugged In, as in "The reason your mouse doesn't work is because of an NPI error."

NPL

Non Performing Loan. A euphemism for a loan which has gone bust. The borrower is no longer paying the lender interest or principal. In the late 1990s and early 2000s, Japanese banks had oodles of NPLs on their balance sheets. They typically carried the NPLs at the full theoretical value of the loan ” the full amount they'd loaned to a borrower plus the interest he was committed to pay. These loans were carried as "assets" on the banks' balance sheets and made them look financially stronger than they really were. American banks are obliged to write NPLs off their balance sheets.

NPM

Network Process Monitor.

NPR

DOA is Dead On Arrival. And it's a term several manufacturers use to refer to equipment which arrives at the customer's premises not working. A person who receives a DOA machine will ask the company for a NPR number ” New Product Return number. This allows them to return the product and have the factory replace it with another new one.

NPRM

Notice of Proposed Rule Making. A term used in regulatory agencies. The agency runs an idea up the flagpole , then typically hold hearings to find out how people react .

NPS

Network Product Support.

NPSI

IBM X.25 NCP Packet Switching Interface. Networking software package that allows Systems Network Architecture (SNA) 3270 traffic to be transmitted over an X.25 packet data network (PDN). See also QLLC. Contrast with DSP.

NPSP

Network Products and Systems Planning.

NPU

1. Listing for the phone number is not in the printed Directory nor is it available from Directory Assistance.

2. Network Processor Unit. Typically a microprocessor that does communications functions.

3. Network Processing Unit. Typically a microprocessor that does communications functions.

NQM

Megalink Channel Service.

NQP

Megalink Channel Service.

NRAM

Nonvolatile Random Access Memory. NRAM does not lose its memory when you turn off the computer or phone system. Many modems, for example, use nonvolatile memory to store configuration information (in place of the switches used on other modems). The command &W writes instructions to the NRAM in many PC modems.

NRC

1. Non-Recurring Charge.

2. Network Reliability Council.

3. The National Research Council of Canada is the main federal scientific and technical research organization. See www.nrc.ca.

NRCE

Non-Redundant Common Equipment.

NRDA

National Routing and Database Administration.

NREN

The National Research and Education Network, an ultragigabit network established by legislation in 1991 by the U.S. House and Senate. Preliminary steps toward deploying this information superhighway (for talking between University computers) include some gigabit network testbeds and the cutover to a 45 megabit per second backbone for the National Science Foundation Network (NSFnet) used by the scientific research and university community nationwide .

NRLLDB

See National Repository Line Level Database.

NRM

1. NoRMal response of HDLC. See Normal Response Mode.

2. An ATM term. An ASP service parameter, Nrm is the maximum number of cells a source may send for each forward RM- cell .

NRN

No Response Necessary. A Proposed e-mail convention to prevent endless back-and- forth acknowledgments: "Thanks for the info ." " You're welcome ...hope it helps." "I hope so too. Thanks." By putting NRN at the bottom of your mail, you absolve the receiver from having to reply.

NS Record

Name Server Record. An NS record declares that a given zone is served by a given name server. Every NS record is either a delegation record or an authority Record. If the name of the NS record is the name of the zone it appears in, it is an authority record. If the name of the NS record is that of a descendant zone, then it is a delegation record. BIND, a common Unix DNS server, uses NS records in hint files for telling resolvers where to find root servers.

NRS

1. Network Reconfiguration System.

2. Network Routing System.

3. National Relay Service.

NRT

Near Real Time.

NRTC

National Rural Telecommunications Cooperative. The organization that provides telecommunications services to rural electric and rural telephone cooperatives in the United States.

NRTL

Pronounced "nurtle." Nationally Recognized Test Laboratory. A laboratory that is nationally recognized for the performance of certain tests on equipment or cable systems for compliance with various standards or legal requirements. UL (Underwriters Laboratories) is a NRTL. See also UL.

NRUG

National Rolm Users Group.

NRZ

Non-Return to Zero. A binary encoding scheme in which ones and zeroes are represented by opposite and alternating high and low voltages and where there is no return to a zero (reference) voltage between encoded bits. NRZ is now used as an encryption scheme for getting data onto and off hard disk fast. It eliminates the need for clock pulses and yields up to 18.5 kilobytes per track and high read/write speeds.

NRZI

Non-Return to Zero Inverted. A binary encoding scheme that inverts the signal on a "one" and leaves the signal unchanged for a "zero". Where a change in the voltage signals a "one" bit, and the absence of a change denotes a "zero" bit value. Also called transition coding.

NS-CPE

Non-Standard Customer Premise Equipment.

NS/EP Telecommunications

National Security and Emergency Preparedness Telecommunications. A Federal government definition. Telecommunications services that are used to maintain a state of readiness or to respond to and manage any event or crisis (local, national, or international) that causes or could cause injury or harm to the population, damage to or loss of property, or degrade or threaten the national security or emergency preparedness of the United States.

NSA

1. Network Service Address. NSAs are unique addresses that define physical or logical locations in equipment, such as a residential telephone number (TN).

2. National Security Agency. An agency of the Federal Government, created in 1952 in a top-secret presidential order issued by Harry Truman. The agency was cloaked in secrecy until the 1982 publication of James Bamford's book, "The Puzzle Palace." NSA is the Federal agency responsible for the design and use of nonmilitary encryption technology, developing sophisticated codes to scramble data, voice or video information. In short, it is charged with signals intelligence and is widely assumed to monitor all communications traffic (phone, fax, data, video, etc.) into and out of the United States with foreign countries. It is barred from intercepting domestic communications. NSA grabbed the headlines in 1993 and 1994 when it adopted its most visible attempt to outgun cybervillains with something called the Clipper Chip. The idea is that the Clipper Chip (a microprocessor) would be installed in every phone, computer, and personal digital assistant in America would carry a device identification number or electronic "key" ” a family key and unit key unique to each Clipper Chip. The device key is split into two numbers that, when combined into what's called a Law Enforcement Access Field number, can unscramble the encrypted messages. The device keys and the corresponding device numbers, according to NSA proposals, would be kept by the US government through key escrow agents. Under a plan proposed, the attorney general would deposit the two device keys in huge, separate electronic database vaults. One key would be held by the National Institute for Standards and Technology (NIST) and the other by the Automated Systems Division of the U.S. Treasury. Access to these keys would be limited to government officials with legal authorization to conduct a digital wiretap. When a law enforcement agency wants to tap into information encrypted by the Clipper Chip, they must obtain a court order and then apply to each of the escrow agents. The agents electronically send their key into to an electronic black box operated by the law enforcement agency. When these keys are electronically inserted, encrypted conversations stream into the black box and come as standard voice transmissions or as ASCII characters in the case of electronic mail. At least that's the theory. American Industry resisted the Clipper Chip and NSA backed down, only to start pumping for something Fortezza. See NSA Line Eater.

Since I wrote the above, NSA has sort of come part way of its secret shell. It's now got its own Web site, www.nsa.gov, in which it describes itself thus: The National Security Agency (NSA) was established by Presidential directive in 1952 as a separately organized agency within the Department of Defense under the direction, authority, and control of the Secretary of Defense, who acts as Executive Agent of the U.S. government for the production of communications intelligence (COMINT) information.

The Central Security Service (CSS) (which is part of NSA) was established by Presidential memorandum in 1972 in order to provide a more unified cryptologic organization within the Department of Defense. The Director, NSA, serves as chief of the CSS and exercises control over the signals intelligence activities of the military services. The resources of NSA/CSS are organized for the accomplishment of two national missions:

The information systems security or INFOSEC mission provides leadership, products, and services to protect classified and unclassified national security systems against exploitation through interception, unauthorized access, or related technical intelligence threats. This mission also supports the Director, NSA, in fulfilling his responsibilities as Executive Agent for interagency operations security training.

The foreign signals intelligence or SIGINT mission allows for an effective, unified organization and control of all the foreign signals collection and processing activities of the United States. NSA is authorized to produce SIGINT in accordance with objectives, requirements and priorities established by the Director of Central Intelligence with the advice of the National Foreign Intelligence Board. Executive Order 12333 of 4 December 1981 describes in more detail the responsibilities of the National Security Agency. See Fortezza and Sigint. www.nsa.gov.

NSA Line Eater

The more paranoid Internet users believe that the National Security Agency has a super-powerful computer assigned to reading everything posted on the Net. They will jokingly refer to this line eater in their postings. Goes back to the early days of the Internet when the bottom lines of messages would sometimes disappear for no apparent reason.

NSAP

Network Service Access Point. The point at which the OSI Network Service is made available to a Transport entity. The NSAPs are identified by OSI Network Addresses. The NSAP is a generic standard for a network address consisting of 20 octets. ATM has specified E.164 for public network addressing and the NSAP address structure for private network addresses.

NSAP-Selector

A component of an Network Service Access Point (NSAP)-Address used to select the Network Layer service user. The NSAP-Selector is sometimes referred to as a Transport-Selector; however, a user of the Network Layer need not be a transport service.

NSAPI

Netscape Server Application Programming Interface. A Netscape-only Web server application development interface, developed by Netscape Communications Corporation. NSAPI was designed as a more robust and efficient replacement for CGI.

NSC

1. Network Service Center. See Network Control Point and SDN.

2. Non-Standard facilities Command. A response to the called fax DIS response.

NSCP

National Scalable Cluster Project. A consortium of universities and corporate partners dedicated to developing distributed computing and deploying high-speed networking through ATM technology. The project is intended to solve the technical hardware and software problems associated with the support of sophisticated multi-processing at widely separated locations. The meta-cluster will operate over an ATM-based WAN; cluster computing within the LAN domain is emerging as a scalable and cost effective to supercomputing and massively parallel computing. Applications are anticipated to include digital libraries and linguistic data, imaging and virtual reality, and data mining. Initial participants include the University of Pennsylvania; the University of Illinois at Chicago; and the University of Maryland, College Park.

NSE

1. Network Support Element.

2. Network Surveillance Engineer.

3. Network Systems Engineer.

NSE/OES

Network Support Element/Operator Evaluation System.

NSDETP

Network Systems Development Electronic Transaction Processing.

NSDP-B&S

Non-Signaling Data Protocol for Billing and Settlements.

NSDP-F

See Non-Signaling Data Protocol for Fraud.

NSEP Telecommunications

See NS/EP Telecommunications.

NSESS

Network Systems Engineering Systems Support.

NSF

1. National Science Foundation.

2. Network Specific Facilities.

NSIF

Network and Services Integration Forum. A not-for-profit membership organization sponsored by ATIS (Alliance for Telecommunications Industry Solutions), NSIF intends to "provide an open industry forum for the discussion and resolution of multiple technology integration and SONET interoperability issues and to enable delivery of services across a set of networks, leading to the definition of recommendations and strategies." Members include equipment vendors , service providers, and other industry players. See also ATIS.

NSFNET

National Science Foundation's TCP/IP-based NETwork, funded by the U.S. Government. Linking supercomputing centers and over 2500 academic and scientific institutions across the world, largely through the Internet, the NSFNET was founded in 1985. It was officially retired in 1995, replaced by the MERIT Network, which now has been replaced by the vBNS (Very high-speed Backbone Network Service). See also NREN, MERIT, and vBNS.

NSG

National Systems Group. Division of Canadian telcos responsible for multiple accounts ” large customers with service in multiple telephone company territories.

NSLOOKUP

Name Server Lookup. An interactive query program of the InterNIC DNS (Domain Name Server). NSLOOKUP allows the user to contact servers to request information about a specific host or to print a list of hosts in the domain. See Internic, DNS, WHOIS, RWHOIS and DIG.

NSO

1. National Services Organization. An NSO provides the interconnecting network infrastructure, intelligent network services, network management, and roaming in a national Personal Communications Network (PCN). An NSO has ownership of resources that allow it to provide services to local operators. Operations such as marketing are centralized.

2. National Switch Operations.

NSP

1. Network Service Provider. Can include a local telephone company, ISP, or CLEC.

2. Native Signal Processing. Intel's idea to use the "spare MIPS" on its Pentium, Pentium Pro and later versions to take over the processing that once dedicated chips, like DSPs, used to do. The idea, clearly, is to sell more Intel chips and fewer chips from other makers .

3. Network Service Plan.

NSR

1. Non-Source Routed: Frame forwarding through a mechanism other than Source Route Bridging.

2. Number Portability Surcharge.

NSS

1. Non Standard Facilities Setup command, a response to an NSF frame.

2. Network and Switching Sub-system. A wireless telecommunications term. The part of the GSM (Global System for Mobile Communications) system in charge of the management of calls and the interface with other networks.

3. Network Status Subsystem.

4. Network Support System.

NSTHS

Network Systems Technical Support.

NSTS/NSS

Network Systems Technical Support/Network Systems Support.

NSU

Network Synchronization Unit. A timing distribution system that provides synchronization signals to all electronic equipment within a wireline network node or office.

NT

1. Network Termination. Network Termination represents the termination point of a Virtual Channel, Virtual Path, or Virtual Path /Virtual Channel at the UNI. See NT-1.

2. New Technology, usually known as Windows NT. It's a new operating system from Microsoft which will let Windows run on high-end machines, such as file servers and workstations. NT has two sets of goals: to provide true multi-tasking, security, network connectivity and 32-bit power. Secondly, it's to provide a smooth upgrade path from Windows and MS-DOS. For a much larger explanation, see Windows NT and Windows NT Advanced Server.

3. Night transfer of ringing and station class of service.

NT-1

National ISDN 1. See ISDN.

NT-2

National ISDN 2. See ISDN.

NT-3

National ISDN 3. See ISDN.

NT1

Network Termination type 1. An ISDN term. The NT1 provides functions related to the physical and electrical termination of the local loop between the carrier network and the user premise. These functions, which fall into Layer 1 of the OSI Reference Model, are necessary to support multichannel digital communications over the loop, support loopback testing, and a variety of other functions. NT1 functions are required for both BRI (Basic Rate Interface), also known as 2B+D, and PRI (Primary Rate Interface), also known as 23B+D. See Network Termination type 1 for a more detailed explanation. See also BRI, ISDN, NT2, NT12, OSI Reference Model and PRI.

The NT1 is the first customer premise device on a two-wire ISDN circuit coming in from the ISDN central office. It does several things. It converts the two-wire ISDN circuit (called "U" interface) to four-wire so you can hook up several terminals ” like a voice phone and a videophone. The NT1 typically has several lights on it which indicate if it's working. An ISDN central office can usually "talk" to the NT1 and do testing and maintenance by instructing the NT1 to loop signals back to the central office. An NT1 will support up to eight terminal devices, though I've never seen it work with that many. The basic NT1 functions are:

• Line transmission termination.

• Layer 1 line maintenance functions and performance monitoring.

• Layer 1 multiplexing, and

• Interface termination, including multi drop termination employing layer 1 contention resolution.

Increasingly, NT1s are being incorporated into customer premises equipment, like phones, PC ISDN data cards, etc.

See ISDN.

NT12

Network Termination type «. An ISDN term for a NT2 device which supports both NT1 and NT2 functionality. Such a device performs functions described in Layers 1 and 2, and perhaps Layer 3, of the OSI Reference Model. See also NT1 and NT2.

NT2

In ISDN, the Network Termination type 2 is an intelligent CPE (Customer Premise Equipment) switching or concentrating device (e.g., PBX, ACD, router, or concentrator). A NT2 device typically terminates PRI (Primary Rate Interface), also known as 23B+D (or 30B+D in Europe), access lines from the local ISDN CO switch. Depending on the specific nature of the NT2 device, it performs protocol handling functions described in Layers 1, 2 and 3 of the OSI Reference Model. See also BRI, ISDN, NT1, NT12, OSI Reference Model and PRI.

NTACS

Narrow TACS. Cellular radio system deployed in Japan using narrow band technology to increase capacity by splitting TACs channels into two narrow channels.

NTAS

Network Traffic Analysis System.

NTCA

National Telecommunications Cooperative Association. A trade association representing primarily rural telephone cooperatives and other small telephone companies. It used to be called National Telephone Cooperative Association. www.ntca.org.

NTD

Netwon's Telecom Dictionary. What else?

NTE

1. Network Termination Equipment. The equipment on both sides of a subscriber line. A term used in the DSL (Digital Subscriber Line) world. See ADSL, ATU-C, ATU-R, and xDSL.

2. Network Transmission Elements.

NTF

No Trouble Found.

NTFS

Windows NT file system; an advanced file within the Windows NT operating system. It supports file system recovery, extremely large storage media, and various features for the POSIX subsystem. It also supports object-oriented applications by treating all files as objects with user-defined and system-defined attributes.

NTI

1. Northern Telecom Inc. Now called Nortel Networks Limited.

2. Network Terminating Interface. A. The point where the network service provider's responsibilities for service begin or end, or B. The interface between DCE and its connected DTE.

NTIA

National Telecommunications and Information Administration. An agency of the U.S. Department of Commerce concerned with spectrum management, public safety (e.g., electromagnetic fields), and communications (primarily telephony) standards. The NTIA is responsible for managing the Federal government's use of the spectrum, while the FCC is responsible for managing the use of spectrum by the private sector, and state and local governments . Clearly, the two agencies work closely in such matters. Both the FCC and the NTIA serve to represent the U.S. at the biannual World (Administrative) Radio- communications Conference (WRC, pronounced "wark" as in "cork"), which are sponsored by the ITU (International Telecommunications Union) every two years. The NTIA also serves as the principal adviser to the President, Vice President and Secretary of Commerce on issues of domestic and international communications and information. The NTIA has been highly instrumental in furthering the concept of the NII (National Information Infrastructure). www.ntia.doc.gov See FCC, ITU, NII and WARC.

NTIS

National Technical Information Service. www.ntis.gov. See National Technical Information Service.

NTN

See Network Terminal Number.

NTO

Network Terminal Option. An IBM program product that enables an SNA network to accommodate a select group non-SNA asynchronous and bisynchronous devices via the NCP-driven communications controller.

NTP

1. Network Termination Point.

2. The Network Time Protocol was developed to maintain a common sense of "time" among Internet hosts around the world. Many systems on the Internet run NTP, and have the same time (relative to Greenwich Mean Time), with a maximum difference of about one second.

NTS

1. Network Test System.

2. Non-Traffic-Sensitive commercial line costs levied on the user.

3. Number Translation Services.

NTSC

National Television Standards Committee. It is the committee of Electronic Industries Association (EIA) that prepared the specifications standards approved by the Federal Communications Commissions in 1953 for commercial analog color TV broadcasting in the United States. The initials are used to describe the method of analog television transmission in the U.S., Canada, Japan, Central America and half of South America. The NTSC system uses interlaced scans and 525 horizontal lines per frame at a rate of 30 frames per second. The picture information is transmitted in AM (amplitude modulation) and the sound information is transmitted in FM (frequency modulation). NTSC is compatible with ITU-R (nee CCIR) Standard M. NTSC is not the only method of transmitting TV in the world. PAL (which stands for Phase Alternate Line) is the name of the format for color TV signals used in West Germany, England, Holland, Australia and several other countries. It uses an interlaced format with 25 frames per second and 625 lines per frame. The extra lines ” 625 versus 525 ” makes PAL a bit "crisper." NTSC and PAL are not compatible. You cannot view an Australian videotape on a U.S. TV, for example.

The background to the NTSC signal is simple. Before NTSC there were millions of black and white TV receivers being used in the USA in the 1940s and early 1950s. As color came along, a color broadcast standard compatible with black and white sets was needed. The idea was that the signal would go out in color. If you had a black and white TV, you could see it in black and white. If you had a color TV, you could see the same signal in color. The method used was to encode the color information separately from the black and white information, and thus to broadcast two signals, called the luminance and chrominance signals. This gives good color reproduction for video, but broadcast TV suffers from phase shifts in the signal caused by reflections from buildings . This gives rise to hue changes, a solution to which was to include an auto-tint circuit in the TV set to reduce the hue fluctuations.

Another solution to the problem with the NTSC standard was adopted in some parts of Europe (and now in Brazil, Africa and Australia). The color signal reverses its phase (direction) on every second line, in order to cancel out any phase shift. This is called Phase Alternate Lines (PAL). Although PAL achieves stable hues it can reduce the color saturation, which luckily is less of a problem.

The French (God bless them for being different) developed a a different color TV system called Sequential Couleur avec Memoire (SECAM). It shares with PAL the ability to display the correct hue, but it also ensures consistent saturation of color. This is still not the perfect solution since the color encoding is by frequency modulation, which can create patterning effects even on non-colored objects. It is used in France, the former Eastern Block countries (OIRT) and some Middle East countries (MESECAM - using an AM encoding). The black and white broadcast system in use had 891 lines! Unfortunately, limited bandwidth meant a color system could not broadcast this amount of information. The number of lines was reduced to 625 lines for color television. It and was therefore incompatible with the black and white TV sets (now a moot anyway, since no one watches black and white TV).

When TV engineers get together to hoist some brews, the initials for the various TV broadcast standards take on other meanings, such as: NTSC, Never Twice the Same Color. PAL, Peace At Last. PAL-M, Peace At Last ” Maybe. SECAM (the French system) becomes System Essentially Contrary to the American Method.

NTSC Signal

National Television Standards Committee specified signal. De-facto standard governing the format of television transmission signals in the United States.

NTSI Format

A color television format having 525 scan lines; a field frequency of 60 Hz; a broadcast bandwidth of 4 MHz; line frequency of 15.75 KHz; frame frequency of 1/30 of a second; and a color subcarrier frequency of 3.58 MHz.

NTT

The Japanese Nippon Telephone and Telegraph Cellular System. The large Japanese company that is 65% government owned. NTT has developed a number of cellular systems operating at 450 MHz and 800 MHz.

NTU

Network Terminating or Termination Unit. A device which is placed at the final interconnect point between the PSTN and the customer owned equipment. NTUs allow the Carrier to isolate their facilities from those of their customers for testing, fault detection, and some service feature functionality.

NU

1. Network unit.

2. Network Unavailable. Equivalent to "All Trunks Busy". The NU tone, an European term, is in Europe is equivalent to "fast busy tone" in the USA.

NuBus

(Pronounced "New Bus.") The name of the bus design for most Apple Macintosh computers. See Nubus Card.

NuBus Card

An add-on card that fits inside the NuBus slots of a Modular Macintosh. Often used for video cards and modems.

Nucleus

An ATM term. The interior reference point of a logical node in the PNNI complex node representation.

NUI

Network User Identifier. A unique alphanumeric number provided to dial-up users to identify them to packet switched networks around the world. The number is used to get onto the network and for billing.

NUID

Network User Identification.

Null

Having no value. A dummy letter, letter symbol, or code group inserted in an encrypted message to delay or prevent its solution, or to complete encrypted groups for transmission or transmission security purposes. See also Null Characters.

Null Call_id

AN ISDN term. A null call_id is the call_id used to convey information that does not pertain to a specific call between the ISDN System Adapter and the central office switch. Null call_ids are primarily used for accessing feature buttons that do not relate to a specific call.

Null Characters

Characters transmitted to fill space, time or to "pad" something. They add nothing to the meaning of a transmitted message, but the null characters are expected by the system. On older teletype machines, for example, when the type head reaches the end of a line and the New Line sequence is transmitted, it usually includes a number of Null Characters in order to give the mechanical type head enough time to reach the left margin of the page before transmitting the next line to the terminal. In this manner, no characters are lost. MCI Mail uses five null characters at the beginning of every line ” unless you tell it otherwise .

NULL Encryption Algorithm

An algorithm that does nothing to transform plaintext data; that is, a no-op. It originated because of IPsec (a collection of IP security measures) ESP, which always specifies the use of an encryption algorithm to provide confidentiality. The NULL encryption algorithm is a convenient way to represent the option of not applying encryption in ESP (or in any other context where this is needed). See IPsec.

Null Fill

A modification of an antenna radiation intended to fill the null areas in an antenna's usual radiation pattern. Null fill use to cover areas which would otherwise fall into an antenna's null zones.

Null Modem

A null modem is either a shortened way of saying "Null Modem Cable" or a device directly connecting two DTE devices. See Null Modem Cable and Crossover Cable.

Null Modem Cable

Crossover or cross-pinned wiring of an RS-232 cable such that a DTE (Data Terminal Equipment) device (such as a PC) can talk to another such device without the use of a modem, hence the term "null", which means "amounting to nothing." A null modem cable allows one PC to connect directly to another PC for file transfer over maximum distances of 50-100 feet (depending on the quality of the cable) without the use of either a modem or a line driver. A null modem cable also can be used to connect one DCE (Data Communications Equipment) device to another, in what is known as a "tail circuit" configuration. Essentially, a null modem cable reverses pins 2 and 3 on an RS-232 cable. But there are no standard null modem cables. And other pins sometimes need changing and jumpering together. Null Modems also are known as Modem Eliminators.

Null spot

An RFID definition. Area in the reader field that doesn't receive radio waves. This is essentially the reader's blind spot. It is a phenomenon common to UHF systems.

Null State

A state in which there is no relationship between a call and device. Synonymous with Idle State.

Null Suppression

A data compression technique whereby streams of null characters are identified at a transmission source and replaced by two or more control characters. The first character indicates the null suppression, and more characters indicate the number of null characters removed. The receiver uses this information to replace the removed data.

Null Value

A parameter or field position for which no value is specified.

Nulls

See Leaky Coax.

NUMA

Non-Uniform Memory Access. A symmetrical multiprocessing (SMP) technology. Proponents claim the technology is an improvement over traditional Intel-based SMP systems that can suffer from traffic jams on their shared-memory buses and typically cannot accommodate more than 16 or 32 processors. With NUMA, each Intel processor has its own local memory and is able to form static or dynamic connections with other chips' memories. NUMA servers can be powered by 64 or more processors.

Number Administration And Service Center

NASC. Provides centralized administration of the Service Management System (SMS) database of 800 numbers. The NASC keeps track of the 800 numbers that are in use, or available for use, by new 800 customers.

Number Capacity

A telephone company term. The network access line capacity of numbers or terminals is the maximum number of network access lines that can be working on installed numbers at the entity's derived objective percent number fill.

Number Cruncher

A number cruncher is a supercharged computer, typically with tens of thousands of microprocessors, that performs complicated calculations. Supercomputers that astrophysicists and chaos theoreticians at universities use are usually referred to as number crunchers.

Number Crunching

Mathematical calculations. "Joe, go do some number crunching and tell if the fundamentals on that stock are any good."

Number Pooling

Number pooling allows local phone companies to share a "pool" (a collection) of telephone numbers with the same exchange. Number pooling is a way to allocate scarce telephone numbers more efficiently . Without pooling, a CLEC (Competitive Local Exchange Carrier) was assigned an entire 10,000 block of phone numbers (for example those on the 212-69X exchange) but might require only a portion of the block, while other phone companies in the same area may be desperate for numbers for their customers. The North American Numbering Council (NANC) developed Thousand Block Number Pooling, also known as 1K Pooling, in order to allow the sharing of numbers in increments of 1,000. For example, one Service Provider (SP) might have 212-691-xxxx block, and another the 212-692-xxxx block. Such pooling can be implemented in areas where Local Number Portability (LNP) is in place. See also CLEC, Local Number Portability, NANC, and Number Portability.

Number Portability

Number Portability (NP) refers to the ability of end users to retain their geographic or non-geographic telephone number when they change any of:

1. Their service provider. This means that users can retain the same telephone number as they change from one service provider (telephone company) to another.

2. Their location. This means that users can retain the same telephone number as they move from one permanent location to another.

3. Their service. This means that users can keep the same telephone number as they move from one type of service to another (e.g., POTS to ISDN).

Number portability started with 800 toll-free numbers as that industry and then moved to local number portability (LNP) as competition developed for local telephone companies. Here's a longer explanation of how 800 number portability developed.

Once upon a time, 800 numbers belonged to the phone companies who supplied 800 service. So if you got 800 service from AT&T and you wanted to keep your number, you were stuck with AT&T. For example, we had (and still have) 1-800-LIBRARY (800-542- 7279). The reason? The database of 800 numbers was maintained by Bellcore, who allocated certain "exchanges," like 800-542, to certain carriers. In the case of 542, it was AT&T. If we wanted to go to a different phone company, we had to give up our phone number. Since many companies had invested vast monies in promoting their 800 numbers, this was inconvenient and, in essence, forced companies to stay with the same long distance company. In 1993, things changed. The FCC mandated Number Portability, which allowed you to change your long distance carrier but keep your valued 800 number. The way the whole thing works now is simple to understand, although somewhat complex and expensive for the carriers to implement. You pick up the phone. You dial an 800-number. Your local central office holds the call for a moment, while it" dips" (checks) into an external, central database of 800 numbers for the routing of that call. (A number of such centralized databases are maintained by the carriers. In other words, the centralized databases are distributed throughout the network in order to balance the load on the processors and associated databases, placing them in strategic proximity to concentrations of traffic.) This database dip typically takes place via the packet-switched SS7 (Signaling System 7) network. When it receives a reply from that external database, it simply then sends the call to the appropriate long distance carrier which is providing service on that 800 number. To change the carrier of your 800 number, simply tell the database who the new carrier is. And that's 800 (actually, 800/888) number portability. See also LNP (Local Number Portability)

As defined by the Telecommunicaitons Act of 1996, the term 'number portability' means the ability of users of telecommunications services to retain, at the same location, existing telecommunications numbers without impairment of quality, reliability, or convenience when switching from one telecommunications carrier to another.

Numbering

To have any sort of network work, everyone on the network has to have a unique number which we can all dial. I only included this definition because I found the following definition in a glossary of LAN terms and I thought, "Maybe someone doesn't know, though if they didn't know, this definition wouldn't help them much." Here's the LAN definition: "The assignment of unique identities to a user-network interface."

Numbering Advisory Committee

See NAC.

Numbering Plan

1. In Wide Area Networks, the method for assigning NNX codes to provide a unique telephone address for each subscriber, special line or trunk destination.

2. In PBXs, the method of assigning extension numbers and trunk designations at the local premises.

Numbering Plan Area

NPA. A fancy term the Bell System came up with years ago to mean Area Codes in North America. NPA/NPA Code. A geographical division in the North American numbering plan within which no two telephones will have the same 7 digit number. "N" originally was any number between "2" and "9"; "P" was always "1" or "0"; and "A" was any number excluding "0" in the electromechanical era of switching machines. Colloquial synonym: "area code." Internationally equivalent to "City Codes" or "Routing Codes" in other nations, where various number sequences may be used.

Numbers Shift

A character in the Baudot code which establishes that the characters following in the transmission are to be interpreted as numeric characters. See Letters Shift.

Numeric Key Pad

A separate section of a computer keyboard which contains all the numerals 0 through 9. Sometimes, some special keys are included ” a plus sign, a minus sign, a multiplication sign and a division sign. The numeric key pad on a computer is the same as that found on calculators and adding machines. The top row is 789. The second top row is 456. The third top row is 123. The lowest row is typically 0, "." and "+". The numeric key pad is exactly opposite that of the touchtone telephone keypad, which was designed deliberately to be unfamiliar to users, so they may not input digits into the nation's telephone system faster than it could take them. Early touchtone central offices were very slow.

Numeric User Identifier

According to the 1988 X.400 recommendations, a numeric user identifier is a standard attribute of an O/R (Originator/Recipient) address that consists of a unique sequence of numbers for identifying a user. (Numeric User Identifier was referred to as Unique Identifier in the 1984 recommendations.)

Numeris

The French name for ISDN.

Numeronym

A telephone number that spells a word. For example, 1-800-542- 7279 is the telephone for the company which distributes this dictionary. That telephone number is advertised as 1-800-LIBRARY. It is a great number to have because it's easy to remember, although it's not so easy to dial. Numeronyms are in great demand, for obvious reasons. With the expansion of the toll-free dialing plan to include 888 (and other prefixes in the near future), it's also important (but increasingly difficult) to protect those numbers from competition.

Nutmeg

In the 16th and 17th centuries, nutmeg was the third most valuable commodity in the world, after silver and gold. In addition to preserving and flavoring food, nutmeg was believed to be a soporific, an emetic, a prophylactic against plague and a hallucinogen. The great naval powers of of Europe at that time ” the Portuguese, Dutch, English and Spanish ” all competed for control of the trade in nutmeg and other spices, including pepper, cinnamon and cloves. Under the Treaty of Breda in 1667, Holland traded New Amsterdam, as the Dutch called Manhattan (i.e. New York City) to the English for Pulau Run, one of the principal nutmeg-growing islands in the Bandas, a series of Islands known as The Spice Islands, which are now part of Indonesia. That was not one of the Dutch's better deals. Nutmeg is reputed to be the secret ingredient in Coca Cola, the beverage and the largest buyer of nutmeg in the world. Most of the world's nutmegs are now not grown in the Spice Islands.

NUXI Problem

The conversion of data between big-endian and little-endian data architectures is known as the NUXI Problem. If the word "UNIX" were stored in two two- byte words, a big-endian system would store it as "UNIX," while a little-endian system would store it as "NUXI." According to legend, the origin of the NUXI Problem refers to the first time that UNIX was ported to the IBM Series 1 minicomputer. The Series 1 had the same size words (two bytes) as the PDP-11, but the bytes were swapped. When the Series 1 machine started up for the first time, it printed out "NUXI" instead of "UNIX". Ever since then, the "NUXI Problem" has referred to byte-ordering problems between machines of different "byte sexes." See Big-endian for a full explanation.

NVOD

Near Video On Demand. Providing a consumer a multimedia item ” movie, TV program, etc. ” on a rotating schedule, thus giving the appearance of an on-demand system, i.e. VOD (Video On Demand).

NVP

1. Network Voice Protocol. Circa 1973 ARPANET protocol. Used to support real-time voice over the ARPANET. Both LPC and CVSD encoding schemes were successfully implemented by Culler-Harrison, Inc., the Information Sciences Institute, Lincoln Laboratory and Stanford Research Institute.

2. In regards to cable, NVP stands for the Nominal Velocity of Propagation. All communications cable has a spec called NVP. An electrical signal in a vacuum would travel at the speed of light. In the world of land-based communications, electrical signals travel through twisted copper pairs at a percentage of the speed of light, around 72% for good cat 5 cable. When you test cat 5 cable, the testing instrument is supposed to be calibrated to the NVP of the cable so that the device can measure the time it takes to go end to end and back (or end to fault and back). Without knowing the NVP, the test device cannot accurately locate a fault in the cable. See also Time Domain Reflectometer. This definition contributed kindly by Steven Waxman.

NVRAM

NonVolatile Random Access Memory. RAM that doesn't lose its memory when you shut the electricity off to it.

NVS

NonVolatile Storage is a storage device, like a disk or EPROM, that retains data when you turn off.

NWL

Non-WireLine. Cellular radio licenses received from the FCC with no initial association to telephone company. Also referred to as A-Block.

NWLink

Microsoft's network protocol that simulates Novell's IPX/SPX for Windows 95 and NT communications with Novell NetWare file servers and compatible devices. NWLink is an IPX/SPX-compatible transport stack that gives NetWare-compatible clients access to NT applications services.

NWRA

National Wireless Resellers Association. A Washington-based trade association and lobbying organization which formerly was known as the NCRA (National Cellular Resellers Association), NWRA merged into TRA (Telecommunications Resellers Association) in 1997. TRA changed its name to ASCENT in 2000. See ASCENT.

NWS

Network Services.

Nx384

N-by 384. The ITU-T's approach to creating a standard algorithm for video codec interoperability It is based on the ITU-T's HO switched digital network standard, which was expanded into the Px64 or H.261 standard, approved in 1990.

Nx64

An ATM term. This refers to a circuit bandwidth or speed provided by the aggregation of nx64 kbps channels (where n= integer> 1). The 64K (64,000 bits per second) or DS-O channel is the basic rate provided by the T Carrier systems. See T Carrier.

NXX

1. In a seven digit local phone number, the first three digits identify the specific telephone company central office code which serves that number. These digits are referred to as the NXX where N can be any number from 2 to 9 and X can be any number. At one stage, many moons ago, it was not permissible to have a 1 or a 0 as the second digit in an NXX and it was called an NNX. But that was before everyone had to dial a "1" before making a direct distance dialed long distance call, whether within their own area code or outside it. This little trick of forcing everyone to dial "1" for long distance allowed us to introduce telephone exchanges with the same three digits as area codes. For example, one of our company's numbers is 212-206-6660. The "206" elsewhere is an area code for Seattle and other parts of Washington state.

2. Network Exchange.

NYNEX Corporation

Pronounced "nine X." One of the original seven Regional Holding Companies (RHCs) formed at Divestiture. It included New York Telephone and New England Telephone Company and sundry service and cellular radio companies. The company said its name was spelled in all capitals, thus NYNEX. The New York Times spelled it Nynex. In any event, Nynex no longer exists. The company was merged (read " acquired ") by Bell Atlantic in 1997 and it now is part of Bell Atlantic. Internally, Bell Atlantic refers to Nynex as Bell Atlantic North, but we're not supposed to know that. Internally, some Bell Atlantic people tend to look down on Nynex people as inferior. After all, Bell Atlantic bought Nynex. Anyway, the saga continues. Bell Atlantic later bought GTE and changed its name on June 30, 2000 to Verizon Communications. See Verizon for a neat explanation of where the word Verizon comes from.

Nyetscape

Nickname for AOL's less-than - full-featured Web browser. But this definition has fallen out of favor since AOL bought Netscape, the company, and they've introduced some better Netscape browsers, though why remains a mystery, since all browsers are free.

Nyquist Theorem

In communications theory, a formula stating that two samples per cycle is sufficient to characterize an analog signal. In other words, the sampling rate must be twice the highest frequency component of the signal (i.e., sample 4 KHz analog voice channels 8000 times per second.) The Nyquist Theorem is the mathematical theorem used in the Mu-Law encoding technique used in T-carrier transmission systems. Shannon's Law, a similar but incompatible theorem, is used in E-carrier systems. See also E-Carrier, Shannon's Law, and T-Carrier.

Nyquist, Harry

A distinguished electrical engineer, Harry Nyquist worked in the research department of AT&T and, later, at Bell Telephone Laboratories. In 1924, he published a paper entitled "Certain Factors Affecting Telegraph Speed," which was an analysis of the relationship between the speed of the telegraph system and the number of signal values it used. That paper was refined in 1928, when he published "Certain Topics in Telegraph Transmission Theory." That paper expressed the Nyquist Theorem, which established the principle of sampling continuous signals to convert them to digital signals. The two papers are cited in the first paragraph of Claude Shannon's classic paper, "The Mathematical Theory of Communication." Nyquist also is noted for his pioneering work on a mathematical explanation for thermal noise, sometimes known as "Nyquist noise," and "telephotography," which was AT&T's 1924 version of a fax machine. See also Nyquist Theorem; and Shannon, Claude Elwood.

NZDF

Non Zero Dispersion Shifted Fiber. A type of Dispersion Shifted Fiber that is used in long haul, high-speed fiber optical transmission systems. See DSF for a full explanation.