In telephony, the demarcation point is the point at which the public switched telephone network ends and connects with the customer's on-premises wiring. It is the dividing line which determines, responsible for installation and maintenance of wiring and equipment—customer/subscriber, or telephone company/provider; the demarcation point has changed over time. Demarcation point is sometimes DMARC, or similar; the term MPOE is synonymous, with the added implication that it occurs as soon as possible upon entering the customer premises. A network interface device serves as the demarcation point. Prior to the Bell System divestiture on January 1, 1984, American Telephone & Telegraph Company through its Bell System companies held a natural monopoly for telephone service within the United States and Canada. AT&T owned the local loop, including the telephone wiring within the customer premises and the customer telephone equipment. A similar arrangement existed with smaller, regional telephone companies such as GTE.
As a result of deregulation of the telephone system, unbundling of the local loop, lawsuits by companies wishing to sell third-party equipment to connect to the telephone network, there was a need to delineate the portion of the network, owned by the customer and the portion owned by the telephone company or the common carrier. Where the portions meet is called the demarcation point; the demarcation point varies from building service level. In its simplest form, the demarcation point is a junction block where telephone extensions join to connect to the network; this junction block includes a lightning arrester. In multi-line installations such as businesses or apartment buildings, the demarcation point may be a punch down block. In most places this hardware existed before deregulation. In the United States, the modern demarcation point is a device defined by FCC rules to allow safe connection of third-party telephone customer-premises equipment and wiring to the Public Switched Telephone Network.
The modern demarcation point is the network interface device or intelligent network interface device known as a "smartjack". The NID is the telco's property; the NID may be indoors. The NID is placed for easy access by a technician, it contains a lightning arrestor and test circuitry which allows the carrier to remotely test whether a wiring fault lies in the customer premises or in the carrier wiring, without requiring a technician at the premises. The demarcation point has a user accessible RJ-11 jack, connected directly to the telephone network, a small loop of telephone cord connecting to the jack by a modular connector; when the loop is disconnected, the on-premises wiring is isolated from the telephone network and the customer may directly connect a telephone to the network via the jack to assist in determining the location of a wiring fault. In most cases, everything from the central office to and including the demarcation point is owned by the carrier and everything past it is owned by the property owner.
As the local loop becomes upgraded, with fiber optic and coaxial cable technologies sometimes replacing the original unshielded twisted pair to the premises, the demarcation point has grown to incorporate the equipment necessary to interface the original premises POTS wiring and equipment to the new communication channel. Demarcation points on houses built prior to the Bell System divestiture do not contain a test jack, they only contained a spark-gap surge protector, a grounding post and mount point to connect a single telephone line. The second wire pair was left unconnected and were kept as a spare pair in case the first pair was damaged. DEMARCs that handle both telephony and IT fiber optic internet lines do not look like the ones pictured above. In many places several customers share one central DEMARC for a strip mall setting. A DEMARC will be located indoors if it is serving more than a single customer; this may impede access. Outdoor ones provide easier access, without disturbing other tenants, but call for weatherproofing and punching through a wall for each new addition of wires and service.
Indoor DEMARC's will be identified by a patch panel of telephone wires on the wall next to a series of boxes with RJ48 jacks for T-1 lines. Each business or individual customer can expect their own separate box for internet access T-1 lines. A demarcation point extension, or demarc extension is the transmission path originating from the interface of the access provider's side of a demarcation point within a premises and ending at the termination point prior to the interface of the edge Customer Premises Equipment; this may include in-segment equipment, media converters and patch cords as required to complete the circuit's transmission path to the edge CPE. A demarc extension is more termed "Service Interface Extension", may be referred to as inside wiring, extended demarc, circuit extension, CPE cabling, riser cabling or DMARC extension. A demarc extension became an important factor to consider in a building's telecommunications infrastructure after the 1984 deregulation of AT&T as well as the supplemental FCC rulings of 1991, 1996 and 1997.
Preceding these rulings, the Bell System Companies held a monopoly and did not allow an interconnection with third party equipment. The incumbent local exchange carriers and other local access providers are now mandated by federal law to provide a point where the operational control or ownersh
Telecommunication is the transmission of signs, messages, writings and sounds or information of any nature by wire, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology, it is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are divided into communication channels which afford the advantages of multiplexing. Since the Latin term communicatio is considered the social process of information exchange, the term telecommunications is used in its plural form because it involves many different technologies. Early means of communicating over a distance included visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, optical heliographs. Other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, loud whistles. 20th- and 21st-century technologies for long-distance communication involve electrical and electromagnetic technologies, such as telegraph and teleprinter, radio, microwave transmission, fiber optics, communications satellites.
A revolution in wireless communication began in the first decade of the 20th century with the pioneering developments in radio communications by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909, other notable pioneering inventors and developers in the field of electrical and electronic telecommunications. These included Charles Wheatstone and Samuel Morse, Alexander Graham Bell, Edwin Armstrong and Lee de Forest, as well as Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth; the word telecommunication is a compound of the Greek prefix tele, meaning distant, far off, or afar, the Latin communicare, meaning to share. Its modern use is adapted from the French, because its written use was recorded in 1904 by the French engineer and novelist Édouard Estaunié. Communication was first used as an English word in the late 14th century, it comes from Old French comunicacion, from Latin communicationem, noun of action from past participle stem of communicare "to share, divide out.
Homing pigeons have been used throughout history by different cultures. Pigeon post had Persian roots, was used by the Romans to aid their military. Frontinus said; the Greeks conveyed the names of the victors at the Olympic Games to various cities using homing pigeons. In the early 19th century, the Dutch government used the system in Sumatra, and in 1849, Paul Julius Reuter started a pigeon service to fly stock prices between Aachen and Brussels, a service that operated for a year until the gap in the telegraph link was closed. In the Middle Ages, chains of beacons were used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance. One notable instance of their use was during the Spanish Armada, when a beacon chain relayed a signal from Plymouth to London. In 1792, Claude Chappe, a French engineer, built the first fixed visual telegraphy system between Lille and Paris.
However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres. As a result of competition from the electrical telegraph, the last commercial line was abandoned in 1880. On 25 July 1837 the first commercial electrical telegraph was demonstrated by English inventor Sir William Fothergill Cooke, English scientist Sir Charles Wheatstone. Both inventors viewed their device as "an improvement to the electromagnetic telegraph" not as a new device. Samuel Morse independently developed a version of the electrical telegraph that he unsuccessfully demonstrated on 2 September 1837, his code was an important advance over Wheatstone's signaling method. The first transatlantic telegraph cable was completed on 27 July 1866, allowing transatlantic telecommunication for the first time; the conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876. Antonio Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849.
However Meucci's device was of little practical value because it relied upon the electrophonic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London. Starting in 1894, Italian inventor Guglielmo Marconi began developing a wireless communication using the newly discovered phenomenon of radio waves, showing by 1901 that they could be transmitted across the Atlantic Ocean; this was the start of wireless telegraphy by radio. Voice and music had little early success. World War I accelerated the development of radio for military communications. After the war, commercial radio AM broadcasting began in the 1920s and became an important mass medium for entertainment and news. World War II again accelerated development of radio for the wartime purposes of aircraft and land communication, radio navigation and radar. Development of stereo FM broadcasting of radio
Automatically switched optical network
ASON is a concept for the evolution of transport networks which allows for dynamic policy-driven control of an optical or SDH network based on signaling between a user and components of the network. Its aim is to automate the connection management within the network; the IETF defines ASON as an alternative/supplement to NMS based connection management. In an optical network without ASON, whenever a user requires more bandwidth, there is a request for a new connection from the user to the service provider; the service provider must manually plan and configure the route in the network. This is not only time consuming, but wastes bandwidth if the user sparingly uses the connection. Bandwidth is becoming a precious resource and expectations from future optical networks are that they should be able to efficiently handle resources as as possible. ASON fulfills some of the requirements of optical networks such as: Fast and automatic end-to-end provisioning Fast and efficient re-routing Support of different clients, but optimized for IP Dynamic set up of connections Support of Optical Virtual Private Networks Support of different levels of quality of service The logical architecture of an ASON can be divided into 3 planes: Transport Plane Control Plane Management PlaneThe Transport Plane contains a number of switches responsible for transporting user data via connections.
These switches are connected to each other via PI. The Control Plane is responsible for the actual resource and connection management within an ASN network, it consists of a series of interconnected via NNIs. These OCCs have the following functions: Network topology discovery Signaling, address assignment Connection set-up/tear-down Connection protection/restoration Traffic engineering Wavelength assignmentThe Management Plane is responsible for managing the Control plane, its responsibilities include Configuration Management of the Control Plane Resources, Routing Areas, Transport resource in Control Plane and Policy. It provides Fault Management, Performance Management and Security Management functions; the Management Plane contains the Network Management Entity, connected to an OCC in Control Plane via the NMI-A and to one of the switches via NMI-T. The traffic from user connected to an ASON network contains data for both Transport and Control Plane; the user is connected to Transport plane via a PI, while it communicates with the Control plane via a UNI.
While ITU has worked on the requirements and architecture of ASON based on the requirements on its members, it is explicitly aiming to avoid the development of new protocols, when existing ones will work fine. The IETF, on the other hand, has been tasked with the development of new protocols in response to general industry requirement. Therefore, while ITU include the PNNI protocol for signaling in the Control plane, IETF has been developing GMPLS as a second option protocol to be used in the Control Plane for signalling; as a product of IETF, GMPLS uses IP to communicate between different components in the Control Plane. The following is a list and description of architecture and requirements as published by ITU-T G.8080/Y.1304, Architecture for the automatically switched optical network G.807/Y.1302, Requirements for automatic switched transport networks Call and Connection Management G.7713/Y.1704, Distributed call and connection management G.7713.1/Y.1704.1, DCM signalling mechanism using PNNI/Q.2931 G.7713.2/Y.1704.2, DCM signalling mechanism using GMPLS RSVP-TE G.7713.3/Y.1704.3, DCM signalling mechanism using GMPLS CR-LDP Discovery and Link Management G.7714/Y.1705, Generalized automatic discovery techniques G.7715/Y.1706, Architecture and requirements of routing for automatic switched transport network G.7716/Y.1707, Architecture and requirements of link resource management for automatically switched transport networks G.7717/Y.1708, ASTN connection admission control.
Other Related Recommendations G.872, Architecture of optical transport networks G.709/Y.1331, Interface for the optical transport network G.959.1, Optical transport network physical layer interfaces G.874, Management aspects of the optical transport network element G.874.1, Optical transport network protocolneutral management information model for the network element view. G.875, Optical transport network management information model for the network element view G.7041/Y.1303, Generic framing procedure G.7042/Y.1305, Link capacity adjustment scheme for virtual concatenated signals G.65x, series on optical fibre cables and test methods G.693, Optical interfaces for intra-office systems G.7710/Y.1701, Common equipment management function requirements G.7712/Y.1703, Architecture and specification of data communication network. G.806, Characteristics of transport equipment. Description methodology and generic functionality