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Fast Automatic Restoration
Fast automatic restoration (FASTAR) is an automated fast response system developed and deployed by American Telephone & Telegraph (AT&T) in 1992 for the centralized restoration of its digital transport network. FASTAR automatically reroutes circuits over a spare protection capacity when a fiber-optic cable failure is detected, hence increasing service availability and reducing the impact of the outages in the network. Similar in operation is real-time restoration (RTR), developed and deployed by MCI and used in the MCI network to minimize the effects of a fiber cut. Restoration techniques It is a recovery technique used in computer networks and telecommunication networks such as mesh optical networks, where the backup path (the alternate path that affected traffic takes after a failure condition) and backup channel are computed in real time after the occurrence of a failure. This technique can be broadly classified into two: centralized restoration and distributed restoration. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT&T
AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile telephone services in the U.S. , AT&T was ranked 13th on the ''Fortune'' 500 rankings of the largest United States corporations, with revenues of $168.8 billion. During most of the 20th century, AT&T had a monopoly on phone service in the United States. The company began its history as the American District Telegraph Company, formed in St. Louis in 1878. After expanding services to Arkansas, Kansas, Oklahoma and Texas, through a series of mergers, it became Southwestern Bell Telephone Company in 1920, which was then a subsidiary of American Telephone and Telegraph Company. The latter was a successor of the original Bell Telephone Company founded by Alexander Graham Bell in 1877. The American Bell Telephone Company formed the American Tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Access And Cross-connect System
A digital cross-connect system (DCS or DXC) is a piece of circuit-switched network equipment, used in telecommunications networks, that allows lower-level TDM bit streams, such as DS0 bit streams, to be rearranged and interconnected among higher-level TDM signals, such as DS1 bit streams. DCS units are available that operate on both older T-carrier/E-carrier bit streams, as well as newer SONET/SDH bit streams. DCS devices can be used for " grooming" telecommunications traffic, switching traffic from one circuit to another in the event of a network failure, supporting automated provisioning, and other applications. Having a DCS in a circuit-switched network provides important flexibility that can otherwise only be obtained at higher cost using manual " DSX" cross-connect patch panels. It is important to realize that while DCS devices "switch" traffic, they are ''not'' packet switches—they switch ''circuits'', not packets, and the circuit arrangements they are used to man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Link Protection
Link protection is designed to safeguard networks from failure. Failures in high-speed networks have always been a concern of utmost importance. A single fiber cut can lead to heavy losses of traffic and protection-switching techniques have been used as the key source to ensure survivability in networks. Survivability can be addressed in many layers in a network and protection can be performed at the physical layer (SONET/SDH, Optical Transport Network), Layer 2 ( Ethernet, MPLS) and Layer 3 ( IP). Protection architectures like Path protection and Link protection safeguard the above-mentioned networks from different kinds of failures. In path protection, a backup path is used from the source to its destination to bypass the failure. In Link protection, the end nodes of the failed link initiate the protection. These nodes detect the fault responsible to initiate the protection mechanisms in order to detour the affected traffic from the failed link onto predetermined reserved path ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-connect
A digital cross-connect system (DCS or DXC) is a piece of circuit-switched network equipment, used in telecommunications networks, that allows lower-level TDM bit streams, such as DS0 bit streams, to be rearranged and interconnected among higher-level TDM signals, such as DS1 bit streams. DCS units are available that operate on both older T-carrier/E-carrier bit streams, as well as newer SONET/SDH bit streams. DCS devices can be used for " grooming" telecommunications traffic, switching traffic from one circuit to another in the event of a network failure, supporting automated provisioning, and other applications. Having a DCS in a circuit-switched network provides important flexibility that can otherwise only be obtained at higher cost using manual " DSX" cross-connect patch panels. It is important to realize that while DCS devices "switch" traffic, they are ''not'' packet switches—they switch ''circuits'', not packets, and the circuit arrangements they are used to man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Availability
In reliability engineering, the term availability has the following meanings: * The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, ''i.e.'' a random, time. * The probability that an item will operate satisfactorily at a given point in time when used under stated conditions in an ideal support environment. Normally high availability systems might be specified as 99.98%, 99.999% or 99.9996%. Representation The simplest representation of availability (''A'') is a ratio of the expected value of the uptime of a system to the aggregate of the expected values of up and down time (that results in the "total amont of time" ''C'' of the observation window) : A = \frac = \frac Another equation for availability (''A'') is a ratio of the Mean Time To Failure (MTTF) and Mean Time To Repair (MTTR), or : A = \frac = \frac If we define the status function X(t) as : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Network
An access network is a type of telecommunications network which connects subscribers to their immediate service provider. It is contrasted with the core network, which connects local providers to one another. The access network may be further divided between feeder plant or distribution network, and drop plant or edge network. Telephone heritage An access network, also referred to as an outside plant, refers to the series of wires, cables and equipment lying between a consumer/business telephone termination point (the point at which a telephone connection reaches the customer) and the local telephone exchange. The local exchange contains banks of automated switching equipment which direct a call or connection to the consumer. The access network is perhaps one of the oldest assets a telecoms operator would own. In 2007–2008 many telecommunication operators experienced increasing problems maintaining the quality of the records which describe the network. In 2006, accordin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure Showing A Failure In An SRLG
Figure may refer to: General *A shape, drawing, depiction, or geometric configuration *Figure (wood), wood appearance *Figure (music), distinguished from musical motif *Noise figure, in telecommunication *Dance figure, an elementary dance pattern *A person's figure, human physical appearance Arts *Figurine, a miniature statuette representation of a creature *Action figure, a posable jointed solid plastic character figurine *Figure painting, realistic representation, especially of the human form *Figure drawing *Model figure, a scale model of a creature Writing *figure, in writing, a type of floating block (text, table, or graphic separate from the main text) *Figure of speech, also called a rhetorical figure *Christ figure, a type of character * in typesetting, text figures and lining figures Accounting *Figure, a synonym for number *Significant figures in a decimal number Science *Figure of the Earth, the size and shape of the Earth in geodesy Sports *Figure (horse), a st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure Showing SRLG Failure Between B And C
Figure may refer to: General *A shape, drawing, depiction, or geometric configuration *Figure (wood), wood appearance *Figure (music), distinguished from musical motif *Noise figure, in telecommunication *Dance figure, an elementary dance pattern *A person's figure, human physical appearance Arts *Figurine, a miniature statuette representation of a creature *Action figure, a posable jointed solid plastic character figurine *Figure painting, realistic representation, especially of the human form *Figure drawing *Model figure, a scale model of a creature Writing *figure, in writing, a type of floating block (text, table, or graphic separate from the main text) *Figure of speech, also called a rhetorical figure *Christ figure, a type of character * in typesetting, text figures and lining figures Accounting *Figure, a synonym for number *Significant figures in a decimal number Science *Figure of the Earth, the size and shape of the Earth in geodesy Sports *Figure (horse), a sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shared Risk Link Groups
Shared may refer to: * Sharing * Shared ancestry or Common descent * Shared care * Shared-cost service * Shared decision-making in medicine * Shared delusion, various meanings * Shared government * Shared intelligence or collective intelligence * Shared library * Shared morality * Shared ownership * Shared parenting or shared custody * Shared property * Shared reading * Shared secret * Shared services * Shared universe, in fiction * Shared vision planning, in irrigation * Shared workspace Science and technology * Shared medium, in telecommunication * Shared neutral, in electric circuitry * Shared pair, in chemistry *Shared vertex (or shared corner or common corner), point of contact between polygons, polyhedra, etc. *Shared edge, line of contact between polygons, polyhedra, etc. Computing * Shared agenda, in groupware * Shared computing * Shared desktop * Shared data structure * Shared IP address * Shared memory architecture * Shared memory (interprocess communication) * Shar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
