Reverse lookup

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Reverse lookup is a procedure of using a value to retrieve a unique key in an associative array. [1]

Applications of reverse lookup include

See also

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The Domain Name System (DNS) is the hierarchical and decentralized naming system used to identify computers, services, and other resources reachable through the Internet or other Internet Protocol (IP) networks. The resource records contained in the DNS associate domain names with other forms of information. These are most commonly used to map human-friendly domain names to the numerical IP addresses computers need to locate services and devices using the underlying network protocols, but have been extended over time to perform many other functions as well. The Domain Name System has been an essential component of the functionality of the Internet since 1985.

Reference work Publication to which one can refer for confirmed facts

A reference work is a work, such as a book or periodical, to which one can refer for information. The information is intended to be found quickly when needed. Such works are usually referred to for particular pieces of information, rather than read beginning to end. The writing style used in these works is informative; the authors avoid use of the first person, and emphasize facts.

Local exchange carrier (LEC) is a regulatory term in telecommunications for the local telephone company.

E.164 ITU-T Recommendation

E.164 is an international standard, titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks.

Telephone directory Book that lists phone numbers of people and businesses

A telephone directory, commonly called a telephone book, telephone address book, phone book, or the white and yellow pages, is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization that publishes the directory. Its purpose is to allow the telephone number of a subscriber identified by name and address to be found.

Caller identification is a telephone service, available in analog and digital telephone systems, including voice over IP (VoIP), that transmits a caller's telephone number to the called party's telephone equipment when the call is being set up. The caller ID service may include the transmission of a name associated with the calling telephone number, in a service called Calling Name Presentation (CNAM). The service was first defined in 1993 in International Telecommunication Union—Telecommunication Standardization Sector (ITU-T) Recommendation Q.731.3.

Signal Varying physical quantity that conveys information

In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The IEEE Transactions on Signal Processing includes audio, video, speech, image, sonar, and radar as examples of signal. A signal may also be defined as any observable change in a quantity over space or time, even if it does not carry information.

Telephone number mapping is a system of unifying the international telephone number system of the public switched telephone network with the Internet addressing and identification name spaces. Internationally, telephone numbers are systematically organized by the E.164 standard, while the Internet uses the Domain Name System (DNS) for linking domain names to IP addresses and other resource information. Telephone number mapping systems provide facilities to determine applicable Internet communications servers responsible for servicing a given telephone number using DNS queries.

In computing, a directory service or name service maps the names of network resources to their respective network addresses. It is a shared information infrastructure for locating, managing, administering and organizing everyday items and network resources, which can include volumes, folders, files, printers, users, groups, devices, telephone numbers and other objects. A directory service is a critical component of a network operating system. A directory server or name server is a server which provides such a service. Each resource on the network is considered an object by the directory server. Information about a particular resource is stored as a collection of attributes associated with that resource or object.

The telephone number prefix 555 is a central office code in the North American Numbering Plan, used as the leading part of a group of 10,000 telephone numbers, 555-XXXX, in each numbering plan area (NPA). It has traditionally been used only for the provision of directory assistance, when dialing -555-1212.

Reverse or reversing may refer to:

The domain name arpa is a top-level domain (TLD) in the Domain Name System (DNS) of the Internet. It is used predominantly for the management of technical network infrastructure. Prominent among such functions are the subdomains in-addr.arpa and ip6.arpa, which provide namespaces for reverse DNS lookup of IPv4 and IPv6 addresses, respectively.

In computer networks, a reverse DNS lookup or reverse DNS resolution (rDNS) is the querying technique of the Domain Name System (DNS) to determine the domain name associated with an IP address – the reverse of the usual "forward" DNS lookup of an IP address from a domain name. The process of reverse resolving of an IP address uses PTR records. rDNS involves searching domain name registry and registrar tables. This may be used to try to identify the originator’s domain name to track, for example, a spammer sending spam emails or the domain name of a computer trying to break into a firewall or someone trying to hack the system. It may also be used to determine the name of the internet service provider assigned to a particular IP address. The reverse DNS database of the Internet is rooted in the .arpa top-level domain.

DNS zone Part of the Internets Domain Name System (DNS) organization system

A DNS zone is a specific portion of the DNS namespace in the Domain Name System (DNS), which is managed by a specific organization or administrator. A DNS zone is an administrative space that allows for more granular control of the DNS components, such as authoritative nameserver. The DNS is broken up into many different zones, which are distinctly managed areas in the DNS namespace. DNS zones are not necessarily physically separated from one another, however, a DNS zone can contain multiple subdomains and multiple zones can exist on the same server.

A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed. Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records.

A reverse telephone directory is a collection of telephone numbers and associated customer details. However, unlike a standard telephone directory, where the user uses customer's details in order to retrieve the telephone number of that person or business, a reverse telephone directory allows users to search by a telephone service number in order to retrieve the customer details for that service.

Directory (computing) File system structure for locating files

In computing, a directory is a file system cataloging structure which contains references to other computer files, and possibly other directories. On many computers, directories are known as folders, or drawers, analogous to a workbench or the traditional office filing cabinet. The name derives from books like a telephone directory that lists the phone numbers of all the people living in a certain area.

The line information database (LIDB) is a collection of commercial databases used in the United States and Canada by telephone companies to store and retrieve Calling Name Presentation (CNAM) data used for caller ID services. In Canada, it is common for the client to apply their own Caller ID information, and this is allowed, provided the regulations regarding spoofing and fraud are not violated. The databases map telephone numbers to 15-character strings of caller names. Class 5 telephone switches, which provide end-office services in exchange areas, use the Signaling System 7 (SS7) signaling protocol to query the database.

A call detail record (CDR) is a data record produced by a telephone exchange or other telecommunications equipment that documents the details of a telephone call or other telecommunications transactions that passes through that facility or device. The record contains various attributes of the call, such as time, duration, completion status, source number, and destination number. It is the automated equivalent of the paper toll tickets that were written and timed by operators for long-distance calls in a manual telephone exchange.

NumberGuru

NumberGuru is a website and smartphone application that allows users to look up the owner of an entered telephone number. Developed by BeenVerified, it can be accessed through its website and smartphone applications for iPhone, Windows Mobile, and Android. It aggregates 99% of landline phones and approximately 50% of domestic cell phones. It also collects data on toll-free and telemarketing callers. It was reported that it averaged approximately 864,000 look-ups per day shortly after its launch in May 2011. It was also listed as a Top 10 Utility App and Top 150 Free Apps Overall by App Annie.

References

  1. Downey, Allen (2012), Think Python, O'Reilly Media, p. 125, ISBN   9781449330729 .
  2. Sheresh, Beth; Sheresh, Doug (2001), Understanding Directory Services, Sams Publishing, p. 237, ISBN   9780672323058 .
  3. Lane, Carole A. (2002), Naked in Cyberspace: How to Find Personal Information Online, Information Today, Inc., p. 144, ISBN   9780910965507 .