In telecommunications, a channel service unit (CSU) is a line Bridging device for use with T-carrier that:
In the evolution of modern telecommunications systems there was a requirement to connect large numbers of low-speed access devices with large telephone company 'central office' switches over common paths. During the first generations of digital networks, analog signals were digitized on line cards attached to the telephone exchange switches. In an effort to reduce local loop costs, it was decided to push this conversion closer to the customer premises by deploying small conversion devices in customer neighborhoods. These devices would combine multiple digital signals on a single link to a larger telephone switch, which would provide service to the customer. These devices were initially called remote concentrators or simply remotes.
In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation point ("demarc"). The demarc is a point established in a building or complex to separate customer equipment from the equipment located in either the distribution infrastructure or central office of the communications service provider.
In telecommunications, a network interface device is a device that serves as the demarcation point between the carrier's local loop and the customer's premises wiring. Outdoor telephone NIDs also provide the subscriber with access to the station wiring and serve as a convenient test point for verification of loop integrity and of the subscriber’s inside wiring.
A digital subscriber line access multiplexer is a network device, often located in telephone exchanges, that connects multiple customer digital subscriber line (DSL) interfaces to a high-speed digital communications channel using multiplexing techniques.
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 who is responsible for installation and maintenance of wiring and equipment—customer/subscriber, or telephone company/provider. The demarcation point varies between countries and has changed over time.
The public switched telephone network (PSTN) 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 most telephones to communicate with each other. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital in its core network and includes mobile and other networks, as well as fixed telephones.
A leased line is a private bidirectional or symmetric telecommunications circuit between two or more locations provided in exchange for a monthly rent. Sometimes known as a private circuit or data line in the UK.
A softswitch is a central device in a telecommunications network which connects telephone calls from one phone line to another, across a telecommunication network or the public Internet, entirely by means of software running on a general-purpose computer system. Most landline calls are routed by purpose-built electronic hardware; however, soft switches using general purpose servers and VoIP technology are becoming more popular.
In telephony, pair gain is the transmitting of multiple POTS signals over the twisted pairs traditionally used for a single traditional subscriber line in telephone systems. Pair gain has the effect of creating additional subscriber lines. This is typically used as an expedient way to solve subscriber line shortage problems by using existing wiring, instead of installing new wires from the central office to the customer premises. The term was invented in the middle 20th century by analogy with earlier use of gain to extend telephone local loops far from the telephone exchange.
Transaction Language 1 (TL1) is a widely used management protocol in telecommunications. It is a cross-vendor, cross-technology man-machine language, and is widely used to manage optical (SONET) and broadband access infrastructure in North America. TL1 is used in the input and output messages that pass between Operations Support Systems (OSSs) and Network Elements (NEs). Operations domains such as surveillance, memory administration, and access and testing define and use TL1 messages to accomplish specific functions between the OS and the NE. TL1 is defined in Telcordia Technologies Generic Requirements document GR-831-CORE.
Digital Signal 1 is a T-carrier signaling scheme devised by Bell Labs. DS1 is the primary digital telephone standard used in the United States, Canada and Japan and is able to transmit up to 24 multiplexed voice and data calls over telephone lines. E-carrier is used in place of T-carrier outside the United States, Canada, Japan, and South Korea. DS1 is the logical bit pattern used over a physical T1 line; in practice, the terms "DS1" and "T1" are often used interchangeably.
A network termination (NT) is a device that connects the customer's data or telephone equipment to a carrier's line that comes into a building or an office. The NT device provides a connection for terminal equipment (TE) and terminal adapter (TA) equipment to the local loop.
In telecommunications, interconnection is the physical linking of a carrier's network with equipment or facilities not belonging to that network. The term may refer to a connection between a carrier's facilities and the equipment belonging to its customer, or to a connection between two carriers.
A passive optical network (PON) is a telecommunications technology used to provide fiber to the end consumer, both domestic and commercial. A PON's distinguishing feature is that it implements a point-to-multipoint architecture, in which unpowered fiber optic splitters are used to enable a single optical fiber to serve multiple end-points. The end-points are often individual customers, rather than commercial. A PON does not have to provision individual fibers between the hub and customer. Passive optical networks are often referred to as the "last mile" between an ISP and customer.
A subscriber loop carrier or subscriber line carrier (SLC) provides telephone exchange-like telephone interface functionality. An SLC remote terminal is typically located in an area with a high density of telephone subscribers, such as a residential neighborhood, that is remote from the telephone company's central office. Two or four T1 circuits connect the SLC remote terminal to the central office terminal (COT), in the case of a universal subscriber loop carrier (USLC). An integrated subscriber loop carrier (ISLC) has its T-spans terminating directly in time division switching equipment in the telephone exchange.
In telecommunications, cable Internet access, shortened to cable Internet, is a form of broadband Internet access which uses the same infrastructure as a cable television. Like digital subscriber line and fiber to the premises services, cable Internet access provides network edge connectivity from the Internet service provider to an end user. It is integrated into the cable television infrastructure analogously to DSL which uses the existing telephone network. Cable TV networks and telecommunications networks are the two predominant forms of residential Internet access. Recently, both have seen increased competition from fiber deployments, wireless, and mobile networks.
Network Termination 1 (NT1) or Network Termination type 1 refers to equipment in an Integrated Services Digital Network (ISDN) that physically and electrically terminates the network at the customer's premises. The NT1 network termination provides signal conversion and timing functions which correspond to layer 1 of the OSI model. In a Basic Rate Interface, the NT1 connects to line termination (LT) equipment in the provider's telephone exchange via the local loop two wire U interface and to customer equipment via the four wire S interface or T interface. The S and T interfaces are electrically equivalent, and the customer equipment port of a NT1 is often labelled as S/T interface. There are many types of NT1 available.
Telecommunications equipment is hardware used for the purposes of telecommunications. Since the 1990s the boundary between telecoms equipment and IT hardware has become blurred as a result of the growth of the internet and its increasing role in the transfer of telecoms data.
