Business Telephone Number


Caller ID Name - Directory Listing or Caller ID Name is the 15 characters delivered to the Called party with the Caller ID.


Customer Service Record - A CSR is a copy of how your telephone records appear in the telephone company’s database.


Direct Inward Dialing, also called Direct Dial-In (DDI) in Europe and Oceania, is a feature offered by telephone companies for use with their customers' private branch exchange (PBX) systems. In DID service the telephone company provides one or more trunk lines to the customer for connection to the customer's PBX and allocates a range of telephone numbers to this line (or group of lines) and forwards all calls to such numbers via the trunk. As calls are presented to the PBX, the dialed destination number (DNIS) is transmitted, usually partially (e.g., last four digits), so that the PBX can route the call directly to the desired telephone extension within the organization without the need for an operator or attendant. The service allows direct inward call routing to each extension while maintaining only a limited number of subscriber lines to satisfy the average concurrent usage of the customer.


Firm Order Commitment - the scheduled installation date for telecommunication services or scheduled transfer date in local number portability.


Purchase or Project Order Number


Keeping Your Existing Telephone Number When You Change Service Provider.  Under the Federal Communications Commission’s “local number portability” (LNP) rules, you can switch telephone service providers, including interconnected Voice over Internet Protocol (VoIP) providers, and keep your existing phone number.  Subscribers can switch from a wireless, wireline, or VoIP provider to any other wireless, wireline or VoIP provider and still keep their existing phone numbers.


Local Number Portability (LNP) for fixed lines, and full mobile number portability (FMNP) for mobile phone lines, refers to the ability of a "customer of record" of an existing fixed-line or mobile telephone number assigned by a local exchange carrier (LEC) to reassign the number to another carrier ("Service Provider Portability"), move it to another location ("Geographic Portability"), or change the type of service ("Service Portability").[1] In most cases, there are limitations to transferability with regards to geography, service area coverage, and technology. Location Portability and Service Portability are not consistently defined or deployed in the telecommunication industry.[2]

LNP was invented by Edward Sonnenberg while working for Siemens. Though it was introduced as a tool to promote competition in the heavily monopolized wireline telecommunications industry,[6] number portability became popular with the advent of mobile telephones, since in most countries different mobile operators are provided with different area codes and, without portability, changing one's operator would require changing one's number. Some operators, especially incumbent operators with large existing subscriber bases, have argued against portability on the grounds that providing this service incurs considerable overhead, while others argue that it prevents vendor lock-in and allows them to compete fairly on price and service. Due to this conflict of interest, number portability is usually mandated for all operators by telecommunications regulatory authorities. In the US, LNP was mandated by the Federal Communications Commission (FCC) in 1996.[6] The mandate required all carriers in the top 100 Metropolitan Statistical Areas (MSAs) to be "LNP-capable" and port numbers to any carriers sending a BFR (bona fide request). The ability to keep a number while switching providers is thought to be attractive to consumers.[7] It was also a major point made by CLECs (Competitive Local Exchange Carriers) preventing customers from leaving ILECs (Incumbent Local Exchange Carriers), thus hindering competition. Details regarding the reasons for LNP and how it is to be implemented can be found in the First Report and Order referenced above.

In the US, the FCC has mandated this in order to increase competition among providers. As of late November 2003, LNP was required for all landline and wireless common carriers, so long as the number is being ported to the same geographical area or telephone exchange. This latest mandate included carriers outside the top 100 MSAs that previously enjoyed a rural carrier exemption.

United States

In the United States, the Federal Communications Commission (FCC) first mandated LNP among wireline carriers in 1997, as well. LNP was first implemented in the U.S. upon the establishment of the original Number Portability Administration Center (NPAC) in Chicago, Illinois in 1998. This service covered select rate centers in the Ameritech region. Thereafter, as switches and telephone networks were upgraded with Local Routing Number (LRN) capability, LNP was deployed sequentially to the remaining Regional Bell Operating Company (RBOC) areas. The U.S. FCC since has mandated Wireless Local Number Portability starting November 24, 2003 (in metropolitan areas), and allowed operators to charge an additional monthly Long-Term Telephone Number Portability End-Use Charge as compensation. On November 10, 2003, the FCC additionally ruled that number portability applies to landline numbers moving to mobile telephones and, on October 31, 2007, the FCC made clear that the obligation to provide LNP extends to VoIP providers.[16]

LNP Project Order

     LNP orders with a quantity of 50 telephone numbers or more is considered a "project".  A "project" requires the following information upon submission:

  • An LOA (letter of authorization) dated and signed within 30 calendar days
  • A current Telephone bill dated within 60 days
  • A simple spreadsheet with all the telephone numbers to be ported without hyphens, parentheses or spaces in a single column
  • A recent customer service record (CSR)

The porting interval for a project is 30 calendar days from the date the project is submitted.



The Public Switched Telephone Network is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators, providing infrastructure and services for public telecommunication. The PSTN consists of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables, all interconnected by switching centers, thus allowing any telephone in the world to communicate with any other. Originally a network of fixed-line analog telephone systems, the PSTN is almost entirely digital in its core and includes mobile as well as fixed telephones.


Responsible Organization - a company which maintains the registration for individual toll-free telephone numbers in the distributed Service Management System/800 database.

Have more questions? Submit a request


Powered by Zendesk